Presensitized plate for preparing lithographic printing plate

ABSTRACT

A presensitized plate for preparing a lithographic printing plate comprises a substrate provided thereon with a light-sensitive layer containing a fluoro-aliphatic group-containing copolymer prepared by copolymerizing at least (A) an addition polymerizable monomer having, on a side chain, a fluoro-aliphatic group in which hydrogen atoms are replaced with fluorine atoms and (B) a (meth)acrylate having an ester chain represented by a specific general formula. The use of the foregoing specific fluorine atom-containing polymer permits the formation of a light-sensitive layer having uniform surface condition without causing abnormality in the surface quality due to the foaming phenomenon observed during the production and also permits the production of a positive light-sensitive resin composition having excellent solubility and dispersibility in a developer.

BACKGROUND OF THE INVENTION

The present invention relates to a novel presensitized plate forpreparing a lithographic printing plate, whose light-sensitive layerincludes a fluoro-aliphatic group-containing copolymer (hereunder alsoreferred to as “fluorine atom-containing polymer”) and more specificallyto a presensitized plate for preparing a lithographic printing plate,which may have uniform coated surface conditions without causing anydefect during preparation such as foaming and which can provide alithographic printing plate excellent in the developing ability andink-receiving properties. The present invention also relates to a methodfor preparing a lithographic printing plate from the presensitized platedescribed above.

A presensitized plate for preparing a lithographic printing plate has aconstruction in which a light-sensitive composition (an image-formingcomposition) is coated on a substrate. A typical production processthereof comprises the steps of applying a light-sensitive compositiondissolved or dispersed in an organic solvent onto a substrate, which hasbeen subjected to an appropriate surface treatment and/or which has beenprovided with an undercoating layer and/or a back coating layer,optionally applying a top coat (or upper) layer such as a protectivelayer and then drying. In addition, a typical plate-making processcomprises the steps of inducing an imagewise change in physicalproperties of a light-sensitive composition applied onto a substrate bythe contact- or projection-type imagewise surface exposure through amask carrying an image or direct exposure according to, for instance,the scanning or modulation of electromagnetic waves based on imageinformation outputted from a computer, removing (or developing) thelight-sensitive layer on the un-exposed areas, followed by, forinstance, optional hydrophilization, lipophilization and formation of aprotective film to thus form a lithographic printing plate comprisingnon-image areas or the exposed hydrophilic substrate surface and imageareas or the surface of the hydrophobic light-sensitive layer. In atypical printing step, the hydrophilic non-image areas on thelithographic printing plate thus prepared receives dampening water,while the hydrophilic image areas formed thereon receives ink to thusform ink images on the surface of the printing plate. The resulting inkimages are directly or indirectly transferred to a desired printingmedium to thus form printed matters.

Regarding the light-sensitive layer (image-forming layer) used in such apresensitized plate, there have been known a wide variety of techniquesrelating to, for instance, light-sensitive layers, which make use ofchanges in physical properties upon exposure to light, such as negativetype one in which the initially soluble type layer is converted intoinsoluble one upon exposure to light and positive type one in which theinitially insoluble type layer is converted into soluble one as well aslight-sensitive layers, which make use of, for instance, opticalreactions, heat mode processes and heat-sensitive recording as theprinciple for inducing such physical property changes. To prepare ahighly useful presensitized plate for lithographic printing plates,irrespective of the kind of the light-sensitive layer selected, a commontechnical problem arises. More specifically, (1) the light-sensitivelayer should have a high uniformity; and (2) the image area should havea high hydrophobicity and the non-image area should easily be removedthrough development. The uniformity of the image area is mainly ascribedto the foregoing preparation process, from the technical standpoint andthe presensitized plate insufficient in the uniformity is not preferredsince it never satisfies such a basic requirement that the printingplate prepared from the presensitized plate should stably provide alarge number of printed matters carrying uniform images of high quality.Moreover, the image area preferably has a high hydrophobicity, sincethis results in the improvement of the resistance thereof to adeveloper, ensures excellent resolution in the plate-making step andalso permits the achievement of sufficient printing durability andsufficient ink-receptivity. However, extremely high hydrophobicity ofthe image area may result in the reduction of the solubility thereof inan alkaline aqueous solution as a commonly used developer and this mayin turn lead to undesirable results such as the insufficient developmentof non-image areas and the generation of sludge components in thedeveloper. More specifically, the light-sensitive layer shouldsimultaneously satisfy two requirements contradictory to one another,i.e., the hydrophobicity of the image area and the easy removability ofthe non-image area. The development of a technique, which can satisfythese two requirements at the same time, is quite difficult and has beenan important problem to be solved.

It has been known that the use of a composition containing afluoro-aliphatic group-containing high molecular weight compound as alight-sensitive composition is quite effective for solving such atechnical problem. For instance, Japanese Un-Examined Patent Publication(hereunder referred to as “J.P. KOKAI”) No. Sho 54-135004 discloses thatthe use of such a composition is effective as a technique for improvingthe uniformity of an image-forming layer. In addition, J.P. KOKAI Nos.Sho 62-170950, Hei 8-15858 and 2000-19724 disclose the usefulness of thecopolymer comprising fluoro-aliphatic group-containing monomer units andspecific functional group-containing monomer units. These techniquespermit the elimination of the insufficiency of the prior arts, whichdisclose the use of a fluoro-aliphatic group-containing polymercompound, by the selection of additional substituents. In other words,these techniques are those for reducing the adverse effect of such afluoro-aliphatic group-containing polymer on the plate-making andprinting processes or, contrary to this, those for making the most useof the effect of the polymer. More specifically, J.P. KOKAI Sho62-170950 discloses further improvement of the film-uniformizingfunction due to the improvement of the surface activity of thelight-sensitive layer; J.P. KOKAI Hei 8-15858 discloses the eliminationof the slow developing ability due to the hydrophobicity, while makinguse of such a polymer; and J.P. KOKAI 2000-19724 discloses the contrastimage-forming effect achieved by the simultaneous satisfaction of thetwo contradictory requirements or the requirements for thehydrophobicity of the image area and the easy removability of thenon-image area, while making use of the hydrophobicity-orientatingability.

Furthermore, it is also possible to device a means for improving thefluoro-aliphatic group-containing polymer other than the selection ofcopolymerizable components. For instance, J.P. KOKAI 2000-187318discloses that the use of a polymer compound derived from monomershaving at least two fluoro-aliphatic groups may provide an image-formingmaterial having excellent ability of discrimination between thesolubilities of the image and non-image areas.

As has been discussed above, the use of a light-sensitive layercontaining a fluoro-aliphatic compound is effective as a method foreliminating the foregoing technical problems (1) and (2) common to thelight-sensitive layer for a presensitized plate used for preparing alithographic printing plate. On the other hand, however, the effect hasstill been insufficient and the development of a further improved suchtechnique has still been desired.

For instance, when using a positive type light-sensitive layer,preferably used for preparing good printed matters are light-sensitivelayers having a high ability of discrimination between the image andnon-image areas or a high gradation (high contrast) obtained afterexposing them to light and then developing from the viewpoint of theimage reproduction and the resistance to defects and there have beendesired for the development of a light-sensitive layer having a highsensitivity, an ability of preventing the formation of an indistinctimage during printing, safety for the light emitted from an incandescentelectric lamp and a high acceptability for development, but there hasnot yet been developed any satisfactory technique.

In this respect, the term “soft tone image” herein used means that whenexposing a light-sensitive layer to light through a step wedge and thendeveloping the exposed light-sensitive layer, the difference between thestep number at which images begin to remain on the substrate and that atwhich the film completely remains thereon is large. On the other hand,the term “high contrast image” herein used means that the foregoingdifference is small.

Regarding the term “formation of an indistinct image during printing”,gases are generated due to the decomposition of the light-sensitivematerial, this in turn leads to the swelling of the litho-film, thisfurther makes the complete contact exposure of the light-sensitive layerimpossible and such a phenomenon is accordingly caused. In general, whenthe clear-sensitivity is set at the same level, the higher the contrastof images, the easier the elimination of the formation of an indistinctimage. Moreover, the term “safety for the light emitted from anincandescent electric lamp is defined to be the stability in sensitivityof images upon exposure of a printing plate to light emitted from anincandescent electric lamp such as a fluorescent lamp and in general,the higher the contrast of images, the higher the safety for the lightemitted from an incandescent electric lamp. In this respect, the stepwedge is a slender rectangular film whose density increases by 0.15 perstep and used for determining the relation between the quantity ofexposed light and the amount of the light-sensitive layer remainingafter the exposure thereof to light and the subsequent developmentthereof. The term “clear-sensitivity” used herein means the sensitivityobserved when an image begins to form after the exposure thereof tolight and the subsequent development thereof. In addition, the term“acceptability for development” is used for evaluating any change in thesensitivity of images after the exposure to light and the subsequentdevelopment, when the concentration of the developer used undergoes achange and, in general, the smaller the change in the sensitivity, thehigher the acceptability for development.

A photo-polymerizable printing plate, which comprises aphotopolymerization initiator and a polymerizable double bond-containingmonomer and is typical of the negative type lithographic printing plate,in particular, a printing plate highly sensitive to laser beams whosewavelength falls within the visible light range and which can directlybe imagewise exposed to a laser beam, the gradation thereof has beensoft and therefore, the presensitized plate easily causes fogging due toscattered light and/or reflected light, when imagewise exposing suchpresensitized plate using an inner drum-type laser plate setter, inwhich the imagewise exposure is performed by fixing such a printingplate and rotating a mirror at a high speed. In general, the printingdurability of a printing plate is improved by exposing to light rayshaving a high energy, but the aforementioned fogging caused due toscattered light and/or reflected light becomes conspicuous in case ofthe photopolymerizable printing plate, the quantity of exposed lightcannot be increased and as a result, the printing durability of theresulting printing plate cannot be improved. For this reason, it isnecessary for the improvement of the printing durability to increase thequantity of light for imagewise exposure and at the same time, toprevent the occurrence of any fogging due to scattered light and/orreflected light. In case of imagewise exposure using a laser beam, thelight-sensitive layer is exposed to laser beam for a time on the orderof about 1 μs per dot, while the fogging due to scattered light and/orreflected light is a phenomenon in which a light-sensitive material isexposed to extremely weak light rays over a long period of time on theorder of several minutes and the light-sensitive layer is thus cured.Therefore, to make the gradation high contrast may be a means forpreventing the fogging. If making the gradation of a light-sensitivematerial high contrast, it is difficult to optically cure the materialwith weak light rays and therefore, the light-sensitive material exposedto weak light can be removed through development and the use of such ahigh contrast light-sensitive material would permit the inhibition ofany fogging.

In addition, in case of heat-sensitive lithographic printing plate,which is imagewise exposed to, for instance, an IR laser beam, thediscrimination between the image and non-image areas is low or such aheat-sensitive printing plate has a low gradation (soft tone).Therefore, the heat-sensitive printing plate suffers from variousproblems in that a developer easily penetrates into the portion on theplate, which comes in contact with the hand, that some of images areskipped during development and that the resulting printing plate shows alow resistance to external defects.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide atechnique for achieving the foregoing subjects (1) and (2) to a levelsuperior to that achieved by the conventional techniques. Morespecifically, the object of the present invention is to provide apresensitized plate for preparing a lithographic printing plate, whichis provided with a light-sensitive layer whose uniformity and solubilityor dispersibility in a developer are improved and which has an abilityof forming high contrast images without entraining any reduction of thesensitivity. It is also an object of the present invention to provide amethod for preparing a lithographic printing plate from thepresensitized plate described above.

The inventors of this invention have conducted various studies toaccomplish the foregoing object and have found that the foregoing objectcan effectively be achieved by the addition of a specific fluorineatom-containing polymer to a light-sensitive layer. More specifically,the present invention has been completed on the basis of the factsdiscovered through the detailed investigations of specificfluoro-aliphatic groups and copolymerizable components.

The present invention relates to a presensitized plate for preparing alithographic printing plate, which comprises a substrate providedthereon with a light-sensitive layer containing a fluoro-aliphaticgroup-containing copolymer prepared by copolymerizing at least thefollowing monomers (A) and (B):

(A) an addition polymerizable monomer having, on a side chain, afluoro-aliphatic group in which hydrogen atoms are replaced withfluorine atoms; and

(B) a (meth)acrylate having an ester chain represented by the followinggeneral formula (I) or (II):

CH₂═C(R¹)—CO—O—R²—O—(CO—R³—O)_(n)—R⁴  (I)

CH₂═C(R¹)—CO—(O—R³—CO)_(n)—O—R⁴  (II)

(In the formulas, R¹ represents —H or —CH₃; R² and R³ each independentlyrepresents an alkylene group having 1 to 12 carbon atoms; R⁴ representsa hydrogen atom or a substituted or unsubstituted alkyl group having 1to 12 carbon atoms, a cycloalkyl group, an aryl group, an aralkyl groupor a heterocyclic group and n is a number ranging from 1 to 50). Thispresensitized plate has been found to show excellent effects withrespect to the foregoing technical subjects (1) and (2). Morespecifically, the presensitized plate comprises a positive typelight-sensitive resin composition, has uniform coated surface conditionswithout causing any abnormality in the surface quality of the plate dueto the foaming encountered when preparing the same and is furtherexcellent in the solubility or dispersibility in a developer.

Moreover, it has also become clear that a negative type presensitizedplate for lithographic printing plates is improved not only in thesurface quality and the solubility in a developer as has already beendiscussed above, but also in the gradation by the addition of a fluorineatom-containing polymer to the light-sensitive layer according to thepresent invention and that the use of such a polymer would permit thepreparation of, in particular, a laser light-sensitivephotopolymerizable presensitized plate quite sensitive to laser lightbeams and excellent in the ability of preventing any fogging due to thescattered light and/or reflected light and also permit the preparationof a printing plate having a high printing durability.

Moreover, in case of a heat-sensitive presensitized plate for alithographic printing plate, it has also become clear that the use ofsuch a fluorine atom-containing polymer would permit the improvement notonly in the surface quality and the solubility in a developer as hasalready been discussed above, but also in the discrimination between theimage and non-image areas and the strength of the images formed.Accordingly, it has been confirmed that the presensitized plate nevercauses any missing of images formed on the portion of the plate, whichcomes in contact with the hand, and can provide a printing plate whosestability to external defects is substantially improved.

Among such effects achieved through the use of such a fluorineatom-containing polymeric compound, the ability of forming a uniformfilm may be ascribed to the surface activity of the polymeric compoundor the ability of reducing the surface tension of a dispersion of alight-sensitive composition in an organic solvent used in thepresensitized plate-making process. In addition, other effectsaccomplished by the use of the fluorine atom-containing polymer compoundmay be ascribed to the high hydrophobicity of the polymer compoundincluded in the light-sensitive layer of the presensitized plate forlithographic printing plates and the abilities of the polymer compoundto undergo orientation, one-sided distribution and localization on thesurface of the light-sensitive layer. In other words, when incorporatingthe fluorine atom-containing polymer compound into a light-sensitivecomposition, the compound may relatively preferentially be distributedin the proximity to the surface of the light-sensitive layer andtherefore, the polymer compound can impart a high hydrophobicity to thesurface of the light-sensitive layer, while maintaining the overall easyremovability of the layer through development.

These properties (uniform film-forming ability and high hydrophobicityof the surface) also widely vary depending on the kinds ofcopolymerizable components used and the incorporation of the esterchains represented by Formulas (I) and (II) into the polymer compoundthrough copolymerization would permit the improvement of the uniformfilm-forming ability and the simultaneous satisfaction of the foregoingrequirements for the hydrophobicity of image areas and the easyremovability of non-image areas. Moreover, the use of such a polymercompound likewise permits the formation of images whose contrast isfurther improved and the improvement of the ink receptivity due to suchan improved hydrophobicity of the image areas.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The polymer compound carrying, on the side chains, fluoro-aliphaticgroups (hereunder also referred to as “fluorine atom-containingpolymer”) used in the present invention will hereunder be described inmore detail.

The fluorine atom-containing polymer used in the present invention is afluoro-aliphatic group-containing copolymer prepared by copolymerizingthe foregoing monomers (A) and (B). The details of monomers (A) and (B)will be described below.

The addition polymerizable monomer moiety in the addition polymerizablemonomer (A) having fluoro-aliphatic groups in which hydrogen atoms oncarbon atoms are replaced with fluorine atoms, usable herein, may be avinyl monomer carrying a radical polymerizable unsaturated group. Amongsuch vinyl monomers, preferably used herein are, for instance, acrylate,methacrylate, acrylamide, methacrylamide, styrenic and vinylic monomers.Specific examples of acrylates and methacrylates carryingfluoro-aliphatic groups bonded thereto are compounds represented by thegeneral formula: Rf—R′—OOC—C(R″)═CH₂ (wherein R′ represents, forinstance, a single bond, an alkylene group, a sulfonamide-alkylene groupor a carbonamide-alkylene group; R″ represents a hydrogen or halogenatom or a methyl group; and Rf represents a perfluoro-aliphatic group).

Specific examples thereof include those disclosed in, for instance, U.S.Pat. Nos. 2,803,615, 2,642,416, 2,826,564, 3,102,103, 3,282,905 and3,304,278; J.P. KOKAI Nos. Hei 6-256289, Sho 62-1116, Sho 62-48772, Sho63-77574 and Sho 62-36657; and those disclosed in J. Chem. Soc. ofJapan, 1985, No. 10, pp. 1884-1888. In addition to these monomers towhich fluoro-aliphatic groups are linked, preferably used herein alsoinclude macromers to which fluoro-aliphatic groups are linked, disclosedin Reports Res. Lab. Asahi Glass Co. Ltd., 1984, 34:27-34. Moreover, thefluoro-aliphatic group-containing monomers usable herein also includemixtures of monomers whose perfluoroalkyl groups have different lengthsrepresented by, for instance, the following structural formula:

CH₂═CH—CO—OCH₂CH₂(CF₂)_(n)F (n=6, 8, 10, 12)

In particular, at least one of the fluoro-aliphatic groups present onside chains of the monomer used in the present invention is preferablyone derived from a fluoro-aliphatic compound according to thetelomerization method (also referred to as “telomer method”) oroligomerization method (also referred to as “oligomer method”). Themethods for preparing these fluoro-aliphatic compounds are detailed in,for instance, “Synthesis and Functions of Fluorine Atom-ContainingCompounds”, 1987, edited by ISHIKAWA Nobuo, published by CMC PublishingCompany, pp. 117-118; and “Chemistry of Organic Fluorine Compounds II”,1995, edited by Milos Hudlicky & Attila E. Pavlath, American ChemicalSociety, pp. 747-752. The telomerization method is a technique forpreparing a telomer, which comprises the step of subjectingfluorine-containing vinyl compounds such as tetrafluoro-ethylene in thepresence of an alkyl halide such as an iodide having a high chaintransfer coefficient as a telogen an example thereof is shown in thefollowing reaction scheme-1).

Reaction Scheme-1:

R—I+nCH₂═CH₂→R—(CF₂CF₂)_(n)—I

The resulting telomer carrying a terminal iodine atom is in generalchemically modified and converted into a fluoro-aliphatic compoundaccording to, for instance, the following “reaction scheme 2”. Further,these compounds are optionally converted into those having desiredmonomer structures and used in the preparation of fluoro-aliphaticgroup-containing polymers.

Incidentally, a part of the fluorine-containing chemical productsprepared by the electrolytic fluorination method, which has favorablybeen used, are less biodegradable, are substances highly biologicallyaccumulative, and may be harmful to fecundity and to growth, althoughthe extent thereof is low. For this reason, the fluorine-containingchemical products prepared by the telomerization method (also referredto as “telomer method”) or the oligomerization method (also referred toas “oligomer method”) are substances having high safety to theenvironment and this is quite advantageous from the industrialstandpoint.

Specific examples of such fluoro-aliphatic group-containing monomersinclude those listed below:

Then the (meth)acrylate (B) carrying a polyester chain used in thefluorine-containing polymer of the present invention as an essentialcomponent will be described below in detail.

Example of such (meth)acrylate (B) carrying a polyester chain arecompounds represented by the following general formula (I) or (II):

CH₂═C(R¹)—CO—O—R²—O—(CO—R³—O)_(n)—R⁴  (I)

CH₂═C(R¹)—CO—(O—R³—CO)_(n)—O—R⁴  (II)

(In the formulas, R¹ represents —H or —CH₃; R² and R³ each independentlyrepresents an alkylene group having 1 to 12 carbon atoms; R⁴ representsa hydrogen atom or a substituted or unsubstituted alkyl group having 1to 12 carbon atoms, cycloalkyl group, aryl group, aralkyl group orheterocyclic group wherein the substituent on the group of R⁴ isselected from the group consisting of alkyl or alkoxy group having 1 to6 carbon atoms and n is a number ranging from 1 to 50).

Among the compounds represented by Formula (I) or (II), particularlypreferably used in the present invention are those represented byFormula (I) or (II) wherein R² and R³ each independently represents analkylene group having 2 to 6 carbon atoms such as —CH₂CH₂—, —CH₂CH₂CH₂—,—(CH₂)₄—, —(CH₂)₅—, —(CH₂)₆— or —CH(CH₃)CH(CH₃)—, R⁴ represents ahydrogen atom or a substituted or unsubstituted alkyl group having 1 to6 carbon atoms and particularly preferably a hydrogen atom or atetrahydro-furfuryl group and n represents the number of polyester unitsand ranges from 1 to 50 and preferably 2 to 10.

All of the foregoing polyester chains may be derived from the same esterunit or may comprise at least two different ester units linked togetherrandomly or in block-like arrangement.

Specific compounds include, for instance, caprolactone-acrylate(ToneM-100 available from UCC Company), caprolactone-modified2-hydroxyethyl acrylate (Plukcel FA Series available from DaicelChemical Industries, Ltd.), caprolactone-modified 2-hydroxyethylmethacrylate (Plukcel FM Series available from Daicel ChemicalIndustries, Ltd.) and caprolactone-modified tetrafurfuryl acrylate(KAYARAD TC Series available from Nippon Kayaku Co., Ltd.).

In the present invention, the fluoro-aliphatic group-containingcopolymer may be prepared by copolymerizing (A) an additionpolymerizable monomer having, on a side chain, a fluoro-aliphatic groupin which hydrogen atoms are replaced with fluorine atoms and (B) a(meth)acrylate having an ester chain represented by the foregoinggeneral formula (I) or (II), as essential components, as well as othermonomers copolymerizable with the foregoing essential components.

The rate of the other monomers to be copolymerized is not more than 30mole % and more preferably not more than 20 mole % on the basis of thetotal molar amount of the monomers.

Such other monomers usable herein may be those disclosed in PolymerHandbook, 2^(nd) ed., J. Brandrup, Wiley Interscience (1975), Chapter 2,pp. 1-483.

Specific examples thereof are compounds each having at least oneaddition polymerizable unsaturated bond selected from the groupconsisting of acrylic acid, methacrylic acid, acrylic acid esters,methacrylic acid esters, acrylamides, methacrylamides, allyl compounds,vinyl ethers and vinyl esters.

Specific examples of such monomers include those listed below:

Acrylic acid esters such as methyl acrylate, ethyl acrylate, propylacrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate,trimethylolpropane monoacrylate, benzyl acrylate, methoxybenzylacrylate, furfuryl acrylate and tetrahydro-furfuryl acrylate;

Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate,propyl methacrylate, chloroethyl methacrylate, 2-hydroxyethylmethacrylate, trimethylol-propane monomethacrylate, benzyl methacrylate,methoxybenzyl methacrylate, furfuryl methacrylate andtetrahydro-furfuryl methacrylate;

Acrylic acid amides such as acrylamide, N-alkyl-acrylamide (the alkylgroup may be those having 1 to 3 carbon atoms such as methyl, ethyl orpropyl group), N,N-dialkyl-acrylamide (the alkyl group may be thosehaving 1 to 3 carbon atoms), N-hydroxyethyl-N-methylacrylamide andN-2-acetamideethyl-N-acetylacrylamide;

Methacrylamides such as mathacrylamide, N-alkyl-methacrylamide (thealkyl group may be those having 1 to 3 carbon atoms such as methyl,ethyl or propyl group), N,N-dialkyl-methacrylamide (the alkyl group maybe those having 1 to 3 carbon atoms),N-hydroxyethyl-N-methyl-methacrylamide andN-2-acetamideethyl-N-acetylmethacryl-amide;

Allyl compounds such as allyl esters (for instance, allyl acetate, allylcaproate, allyl caprylate, allyl laurate, allyl palmitate, allylstearate, allyl benzoate, allyl acetoacetate and allyl lactate) andallyl oxyethanol;

Vinyl ethers such as alkyl vinyl ethers (for instance, hexyl vinylether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether,methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinylether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinylether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether,dimethyl-aminoethyl vinyl ether, diethyl-aminoethyl vinyl ether,butyl-aminoethyl vinyl ether, benzyl vinyl ether and tetrahydro-furfurylvinyl ether;

Vinyl esters such as vinyl butyrate, vinyl isobutyrate, vinyltrimethyl-acetate, vinyl diethyl-acetate, vinyl valerate, vinylcaproate, vinyl chloroacetate, vinyl dichloro-acetate, vinylmethoxy-acetate, vinyl butoxy-acetate, vinyl lactate, vinyl-β-phenylbutyrate and vinyl cyclohexyl-carboxylate;

Dialkyl itaconates such as dimethyl itaconates, diethyl itaconates anddibutyl itaconates;

Dialkyl-esters or monoalkyl-esters of fumaric acid such as dibutylfumarate; and

Other monomers such as crotonic acid, itaconic acid, acrylonitrile,methacrylonitrile, maleylonitrile and styrene.

The amount of the fluoro-aliphatic group-containing monomer (A) used forpreparing the fluorine atom-containing polymer employed in the presentinvention is not less than 5% by weight, preferably 5 to 90% by weight,more preferably 5 to 70% by weight and further preferably 7 to 60% byweight on the basis of the total weight of the monomers constituting thefluorine atom-containing polymer.

On the other hand, the amount of the (meth)acrylate monomer carrying anester chain (B) is not less than 10% by weight, preferably 10 to 95% byweight, more preferably 15 to 70% by weight and further preferably 20 to60% by weight on the basis of the total weight of the monomersconstituting the fluorine atom-containing polymer.

The preferred weight average molecular weight of the fluorineatom-containing polymer used in the present invention ranges from 3,000to 200,000 and more preferably 6,000 to 80,000.

Moreover, the preferred added amount of the fluorine atom-containingpolymer used in the present invention ranges from 0.005 to 8% by weight,preferably 0.01 to 5% by weight and more preferably 0.05 to 3% by weighton the basis of the amount of the light-sensitive resin composition forforming the light-sensitive layer (or the coating components other thanthe solvent used). This is because if the amount of the polymer is lessthan 0.005% by weight, the effect achieved by the addition of thepolymer is insufficient, while if it exceeds 8% by weight, it issometimes difficult to completely dry the coated film and the quality(such as sensitivity) of the resulting light-sensitive material isadversely affected.

The fluorine atom-containing polymer used in the present invention maybe prepared by any known and commonly used method. For instance, thepolymer may be prepared by polymerizing monomers such as the foregoingfluoro-aliphatic group-containing (meth)acrylate and the (meth)acrylatemonomer carrying an ester chain in an organic solvent in the presence ofa currently used radical polymerization initiator. Alternatively, thepolymer may likewise be prepared from the foregoing monomers and otheraddition polymerizable unsaturated compounds using the same method usedabove. The use of, for instance, the dropping polymerization method, inwhich monomers and an initiator are dropwise added to a reactioncontainer, depending on the polymerization ability of every monomersused, is also effective to prepare a polymer having a uniformcomposition.

Moreover, polymers having a high content of fluorine atom are removedby, for instance, filtration through a column, purification throughre-precipitation and/or solvent extraction to thus prevent theoccurrence of any repulsive defect.

Specific examples of the fluorine atom-containing polymer used in thepresent invention will be listed in the following Table, but the presentinvention is not restricted to these specific examples at all. In thefollowing Table 1, each numerical value represents the rate (by weight)of each monomer component and the abbreviations “Fluoro-Monomer”, “EsterChain-Monomer”, “Other Monomer” and “Mw” represent fluoro-aliphaticgroup-containing monomer (A), ester chain-containing (meth)acrylatemonomer (B), other copolymerizable component and weight averagemolecular weight, respectively.

TABLE 1 Fluoro- Ester No. Monomer Monomer Chain- Other Monomer Mw P-1F-1 40 E-1 60 — — 40000 P-2 F-1 40 E-3 60 — — 30000 P-3 F-1 30 E-7 70 —— 50000 P-4 F-5 50 E-2 50 — — 25000 P-5 F-5 60 E-7 40 — — 15000 P-6 F-535 E-11 65 — — 55000 P-7 F-9 40 E-1 60 — — 60000 P-8 F-9 55 E-3 45 — —85000 P-9 F-9 40 E-7 60 — — 40000 P-10 F-9 50 E-7 40 NIPAM 10 80000 P-11F-9 55 E-8 40 MMA  5 45000 P-12 F-9 40 E-9 60 — — 35000 P-13 F-10 45 E-255 — — 15000 P-14 F-10 50 E-8 50 — — 55000 P-15 F-17 40 E-1 60 — — 60000P-16 F-17 50 E-7 50 — — 20000 P-17 F-17 40 E-10 60 — — 30000 P-18 F-1750 E-1 40 HEMA 10 15000 P-19 F-17 50 E-6 45 Aam  5 40000 P-20 F-18 50E-4 50 — — 60000 P-21 F-18 45 E-8 55 — — 15000 P-22 F-38 50 E-6 50 — —20000 P-23 F-38 60 E-7 40 — — 40000 P-24 F-38 70 E-8 30 — — 30000 P-25F-43 40 E-1 60 — — 25000 P-26 F-43 45 E-7 55 — — 20000 P-27 F-47 40 E-160 — — 30000 P-28 F-47 60 E-3 40 — — 40000 P-29 F-47 50 E-7 50 — — 25000P-30 F-47 45 E-7 50 HEMA  5 15000 NIPAM: N-isopropyl-acrylamide; MMA:methyl methacrylate; HEMA: 2-hydroxyethyl methacrylate; Aam: acrylamide.

Then other components required for the preparation of thelight-sensitive resin composition as a composition for forming thelight-sensitive layer in the present invention will hereunder bedescribed in detail.

In the present invention, the light-sensitive resin composition forforming the foregoing fluorine polymer-containing light-sensitive layercomprises at least a light-sensitive compound or a light-heat conversionagent in addition to the foregoing fluorine atom-containing polymer.

A positive type light-sensitive resin composition may be any onecontaining a light-sensitive compound whose solubility or an ability ofswelling undergoes a change before and after the exposure to light, butpreferred such light-sensitive compounds are o-quinonediazide compounds.For instance, in case of a positive light-sensitive resin compositioncontaining an alkali-soluble resin and an o-quinonediazide compound,such an o-quinonediazide compound is a compound having at least oneo-quinonediazido group and preferably such a compound whose solubilityin an alkaline aqueous solution increases after the exposure thereof toactinic light rays.

As such light-sensitive compounds, there have been known those having avariety of structures and the details thereof are disclosed in, forinstance, J. KOSAR, “Light-Sensitive Systems”, 1965, pp. 336-352, JohnWiley & Sons Inc. In particular, compounds preferably used aslight-sensitive compounds for the positive light-sensitive resincomposition are, for instance, combinations of a variety of hydroxylcompounds with sulfonic acid esters of o-benzoquinone-diazide oro-naphthoquinone-diazide.

Examples of such o-quinonediazide compounds are, for instance, esters of1,2-naphthoquinone-2-diazide-5-sulfonyl chloride withphenol-formaldehyde resins or cresol-formaldehyde resins; esters of1,2-naphthoquinone-2-diazide-5-sulfonyl chloride with pyrogallol-acetoneresins as disclosed in U.S. Pat. No. 3,635,709; esters of1,2-naphthoquinone-2-diazide-5-sulfonyl chloride withresorcin-benzaldehyde resins as disclosed in Japanese Examined PatentPublication (hereunder referred to as “J.P. KOKOKU”) No. Sho 63-13528;esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride withresorcin-pyrogallol-acetone copolycondensed resins as disclosed in J.P.KOKOKU No. Sho 62-44257; products obtained by esterification ofpolyesters having terminal hydroxyl groups with1,2-naphthoquinone-2-diazide-5-sulfonyl chloride as disclosed in J.P.KOKOKU No. Sho 56-45127; products obtained by esterification ofhomopolymers of N-(4-hydroxyphenyl) methacrylamide or copolymers of themonomer and other copolymerizable monomers with1,2-naphthoquinone-2-diazide-5-sulfonyl chloride as disclosed in J.P.KOKOKU No. Sho 50-24641; esters of1,2-naphthoquinone-2-diazide-5-sulfonyl chloride withbisphenol-formaldehyde resins as disclosed in J.P. KOKOKU No. Sho54-29922; products obtained by esterification of homopolymers ofp-hydroxystyrene or copolymers of the monomer and other copolymerizablemonomers with 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride asdisclosed in J.P. KOKOKU No. Sho 52-36043; and esters of1,2-naphthoquinone-2-diazide-5-sulfonyl chloride withpolyhydroxy-benzophenone.

Examples of other known o-quinonediazide compounds usable in the presentinvention are those disclosed in, for instance, J.P. KOKAI Nos. Sho63-80254, Sho 58-5737, Sho 57-111530, Sho 57-111531, Sho 57-114138, Sho57-142635 and Sho 51-36129; J.P. KOKOKU Nos. Sho 63-3411, Sho 62-51459and Sho 51-483. The content of the foregoing o-quinonediazide compoundin the light-sensitive resin composition in general ranges from 5 to 60%by weight and more preferably 10 to 40% by weight on the basis of thetotal solid content of the composition.

Light-sensitive compounds used herein other than the o-quinonediazidetype ones are chemical sensitizer type light-sensitive materialscomprising combinations of compounds whose alkaline-soluble groups areprotected with groups susceptible to acid-decomposition withphotolytically acid-generating agents. The photolyticallyacid-generating agents used in the chemical sensitizer system may be anyknown one.

Specific examples thereof include diazonium salts disclosed in, forinstance, S. I. Schlesinger, Photogr. Sci. Eng., 1974, 18:387 and T. S.Bal et al., Polymer, 1980, 21:423; ammonium salts disclosed in, forinstance, U.S. Pat. Nos. 4,069,055 and 4,069,056 and J. P. KOKAI No. Hei3-140140; phosphonium salts disclosed in, for instance, D.C. Necker etal., Macromolecules, 1984, 17:2468, C. S. Wen et al., Tech. Proc. Conf.Rad. Curing ASIA, p. 478, Tokyo, October (1988) and U.S. Pat. Nos.4,069,055 and 4,069,056; iodonium salts disclosed in, for instance, J.V. Crivello et al., Macromolecules, 10 (6), 1307 (1977), Chem. Eng.News, Nov. 28, p. 31 (1988), European Patent No. 104,143, U.S. Pat. Nos.339,049 and 410,201 and J. P. KOKAI Nos. Hei 2-150848 and Hei 2-296514;sulfonium salts disclosed in, for instance, J. V. Crivello et al.,Polymer J., 1985, 17:73, J. V. Crivello et al., J. Org. Chem., 1978,43:3055, W. R. Watt et al., J. Polymer Sci., Polymer Chem. Ed., 1984,22:1789, J. V. Crivello et al., Polymer Bull., 1985, 14:279, J. V.Crivello et al., Macromolecules, 14(5), 1141 81981), J. V. Crivello etal., J. Polymer Sci., Polymer Chem. Ed., 1979, 17:2877, European PatentNos. 370,693, 233,567, 297,443 and 297,442, U.S. Pat. Nos. 3,902,114,4,933,377, 410,201, 339,049, 4,760,013, 4,734,444 and 2,833,827 andGerman Patent Nos. 2,904,626, 3,604,580 and 3,604,581; selenonium saltsdisclosed in, for instance, J. V. Crivello et al., Macromolecules,10(6), 1307 (1977) and J. V. Crivello et al., J. Polymer Sci., PolymerChem. Ed., 1979, 17:1047; onium salts such as arsonium salts disclosedin, for instance, C. S. Wen et al., Tech. Proc. Conf. Rad. Curing ASIA,p. 478, Tokyo, October (1988); organic halogen-containing compoundsdisclosed in, for instance, U.S. Pat. No. 3,905,815, J.P. KOKOKU No. Sho46-4605, J.P. KOKAI Nos. Sho 48-36281, Sho 55-32070, Sho 60-239736, Sho61-169835, Sho 61-169837, Sho 62-58241, Sho 62-212401, Sho 63-70243 andSho 63-298339; organometal/organic halogen-containing compoundsdisclosed in, for instance, K. Meier et al., J. Rad. Curing, 13(4), 26(1986), T. P. Gill et al., Inorg. Chem., 1980, 19:3007, D. Astruc, Acc.Chem. Res., 19(12), 377 (1896) and J.P. KOKAI No. Hei 2-161445;photolytically acid-generating agents disclosed in, for instance, S.Hayase et al., J. Polymer Sci., 1987, 25:753, E. Reichmanis et al., J.Polymer Sci., Polymer Chem. Ed., 1985, 23:1, Q. Q. Zhu et al., J.Photochem., 36, 85, 39, 317 (1987), B. Amit et al., Tetrahedron Lett.,(24), 2205 (1973), D. H. R. Barton et al., J. Chem. Soc., 3571 (1965),P. M. Collins et al., J. Chem. Soc., Perkin I, 1695 (1975), M.Rudinstein et al., Tetrahedron Lett., (17), 1445 (1975), J. W. Walker etal., J. Am. Chem. Soc., 110, 7170 (1988), S. C. Busman et al., J.Imaging Technol., 11(4), 191 (1985), H. M. Houlihan et al.,Macromolecules, 21, 2001 (1988), P. M. Collins et al., J. Chem. Soc.,Chem. Commun., 532 (1972), S. Hayase et al., Macromolecules, 18, 1799(1985), E. Reichmanis et al., J. Electrochem. Soc., Solid State Sci.Technol., 130(6), F. M. Houlihan et al., Macromolecules, 21, 2001(1988), European Patent Nos. 0,290,750, 046,083, 156,535, 271,851 and0,388,343, U.S. Pat. Nos. 3,901,710 and 4,181,531 and J. P. KOKAI Nos.Sho 60-198538 and Sho 53-133022; compounds photolytically decomposedinto sulfonic acid such as imino-sulfonates such as those disclosed in,for instance, M. Tunooka et al., Polymer Preprints Japan, 35(8), G.Berner et al., J. Rad. Curing, 13(4), W. J. Mijs et al., CoatingTechnol., 55(697), 45 (1983), Akzo, H. Adachi et al., Polymer PreprintsJapan, 37(3), European Patent Nos. 0,199,672, 84,515, 199,672, 044,115and 0,101,122, U.S. Pat. Nos. 4,618,564, 4,371,605 and 4,431,774, J.P.KOKAI Nos. Sho 64-18143 and Hei 2-24575 and Japanese Patent ApplicationSerial No. Hei 3-140109; and disulfone compounds disclosed in, forinstance, J.P. KOKAI No. Sho 61-166544.

The added amount of these compounds, which are decomposed by theirradiation with actinic light rays or radiant rays to thus generateacids in general ranges from 0.001 to 40% by weight, preferably 0.01 to20% by weight and more preferably 0.1 to 5% by weight on the basis ofthe total weight of the light-sensitive resin composition (except forthe coating solvent).

Examples of the compounds whose alkaline-soluble groups are protectedwith groups susceptible to acid-decomposition may be those containing—C—O—C— or —C—O—Si— bonds and specific examples thereof are those listedbelow:

(a) Compounds containing at least one member selected from the groupconsisting of ortho-carboxylic acid esters and carboxylic acid amideacetals, these compounds being polymerizable and the foregoing memberbeing able to serve as crosslinking elements in the main chain or asside chains or substituents;

(b) Oligomer-like or polymeric compounds containing, in the main chain,members selected from the group consisting of repeated acetals andketals;

(c) Compounds containing at least one member selected from the groupconsisting of enol esters or N-acylamino-carbonates;

(d) Cyclic acetals or ketals of β-ketoesters or β-ketoamides;

(e) Compounds containing silyl ether groups;

(f) Compounds containing silyl enol ether groups;

(g) Monoacetals or monoketals whose aldehyde or ketone component has asolubility, in a developer, ranging from 0.1 to 100 g/l;

(h) Ethers of tertiary alcohols; and

(i) Carboxylic acid esters and carbonate esters of tertiary allyl- orbenzyl-alcohols.

The foregoing compounds belonging to the foregoing group (a), which arecleavable by the action of an acid are disclosed in German PatentLaid-Open Nos. 2,610,842 and 2,928,636. The mixtures containing thecompounds of Group (b) are disclosed in German Patent Nos. 2,306,248 and2,718,254. The compounds of Group (c) are disclosed in European PatentLaid-Open Nos. 0,006,626 and 0,006,627. The compounds of Group (d) aredisclosed in European Patent Laid-Open No. 0,202,196 and the compoundsof Group (e) are disclosed in German Patent Laid-Open Nos. 3,544,165 and3,601,264. The compounds of Group (f) are disclosed in German PatentLaid-Open Nos. 3,730,785 and 3,730,783 and the compounds of Group (g)are disclosed in German Patent Laid-Open No. 3,730,783. The compounds ofGroup (h) are disclosed in, for instance, U.S. Pat. No. 4,603,101 andthe compounds of Group (i) are disclosed in, for instance, U.S. Pat. No.4,491,628 and the article of J. M. Frechet et al. (J. Imaging Sci.,1986, 30:59-64.

The content of these compounds whose alkaline-soluble groups areprotected with groups susceptible to acid-decomposition in thelight-sensitive resin composition in general ranges from 1 to 60% byweight and more preferably 5 to 40% by weight on the basis of the totalsolid content of the resin composition.

The light-sensitive resin composition used in the invention may furthercomprise a water-insoluble and alkaline aqueous solution-solublesynthetic resin (hereunder referred to as “alkaline-soluble resin”).

Examples of such alkaline-soluble resins are phenol-formaldehyde resins,cresol-formaldehyde resins, phenol-cresol-formaldehyde co-polycondensedresins, phenol-modified xylene resins, polyhydroxy-styrene,poly(halogenated hydroxystyrene), copolymers ofN-(4-hydroxyphenyl)methacrylamide and copolymers of hydroquinonemonomethacrylate, as well as sulfonylamide-containing polymers asdisclosed in J.P. KOKAI No. Hei 7-28244 and carboxyl group-containingpolymers as disclosed in J.P. KOKAI No. Hei 7-36184. Thealkaline-soluble resins also usable herein include a variety ofalkaline-soluble high molecular weight compounds such as phenolichydroxyl group-containing acrylic resins as disclosed in J.P. KOKAI No.Sho 51-34711, sulfonamide group-containing acrylic resins as disclosedin J.P. KOKAI No. Hei 2-866, and urethane-type resins. Thesealkaline-soluble resins or high molecular weight compounds arepreferably those each having a weight average molecular weight rangingfrom 500 to 20,000 and a number average molecular weight ranging from200 to 60,000. Such alkaline-soluble resins or high molecular weightcompounds may be used alone or in any combination of at least two ofthem and the amount thereof added to the light-sensitive composition isnot more than 80% by weight on the basis of the total solid content ofthe composition.

Moreover, as disclosed in U.S. Pat. No. 4,123,279, it is preferred forthe improvement of the ink receptivity of images to use a condensate offormaldehyde with a phenol carrying an alkyl group having 3 to 8 carbonatoms as a substituent, such as t-butylphenol-formaldehyde resin oroctylphenol-formaldehyde resin simultaneously with the foregoingalkaline-soluble resin. Such an alkaline-soluble resin is in generalused in an amount of not more than 90% by weight on the basis of thetotal solid content of the light-sensitive composition.

The light-sensitive resin composition may, if necessary, furthercomprise, for instance, a cyclic acid anhydride for the improvement ofthe sensitivity of the composition, an agent or composition forobtaining a visible image immediately after the imagewise exposurethereof, a dye as an image-coloring agent and other fillers.

The light-sensitive resin composition used in the present inventionpreferably comprises cyclic acid anhydrides, phenols and/or organicacids in order to improve the sensitivity of the resin composition.Examples of such cyclic acid anhydrides are phthalic acid anhydride,tetrahydro-phthalic acid anhydride, hexahydrophthalic acid anhydride,3,6-endoxy-Δ4-tetrahydro-phthalic acid anhydride, tetrachloro-phthalicacid anhydride, maleic acid anhydride, chloro-maleic acid anhydride,α-phenyl-maleic acid anhydride, succinic acid anhydride and pyromelliticacid anhydride. Examples of such phenols are bisphenol A, p-nitrophenol,p-ethoxyphenol, 2,3,4-trihydroxy-benzophenone, 4-hydroxy-benzophenone,2,4,4′-trihydroxy-benzophenone, 4,4′,4″-tri-hydroxy-triphenylmethane and4,4′,3″,4″-tetrahydroxy-3,5,3′,5′-tetramethyl-triphenyl-methane.

Examples of the foregoing organic acids are those disclosed in, forinstance, J.P. KOKAI Nos. Sho 60-88942 and Hei 2-96755 such as sulfonicacids, sulfinic acids, alkylsulfates, phosphonic acids, phosphinicacids, phosphoric acid esters and carboxylic acids and more specificallyinclude p-toluene-sulfonic acid, dodecylbenzene-sulfonic acid,p-toluene-sulfinic acid, ethyl sulfate, phenyl-phosphonic acid,phenyl-phosphinic acid, phenyl phosphate, diphenyl phosphate, benzoicacid, isophthalic acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoate, phthalic acid, terephthalic acid,1,4-cyclohexene-2,2-dicarboxylic acid, erucic acid, lauric acid,n-undecanoic acid and ascorbic acid.

The content of the foregoing cyclic acid anhydrides, phenols and organicacids in the light-sensitive resin composition preferably ranges from0.05 to 15% by weight and more preferably 0.1 to 5% by weight.

The agent or composition for obtaining a visible image immediately afterthe imagewise exposure may be, for instance, combinations oflight-sensitive compounds, which can release acids upon irradiation withlight and organic dyes which change their color tones through thecoupling with acids.

Examples of agents or compositions for obtaining a visible imageimmediately after the imagewise exposure areo-naphthoquinonediazide-4-sulfonic acid halogenide as disclosed in J.P.KOKAI No. Sho 50-36209; trihalomethyl-2-pyrone andtrihalomethyl-s-triazine disclosed in J.P. KOKAI No. Sho 53-36223; avariety of o-naphthoquinonediazide compounds disclosed in J.P. KOKAI No.Sho 55-62444; 2-trihalomethyl-5-aryl-1,3,4-oxadiazole compound disclosedin J.P. KOKAI No. Sho 55-77742; and diazonium salts. These compounds maybe used alone or in combination and the added amount thereof preferablyranges from 0.3 to 15% by weight on the basis of the total solid contentof the light-sensitive resin composition.

The light-sensitive resin composition used in the present inventioncomprises at least one organic dye, which changes its color tone throughthe interaction with the photolytically generated product of a compoundcapable of generating an acidic substance through the photolyticdecomposition. Such organic dyes usable herein are diphenyl methanetype, triaryl methane type, thiazine type, oxazine type, phenazine type,xanthene type, anthraquinone type, imino-naphthoquinone type andazomethine type dyes. Specific examples thereof are those listed below:

Brilliant Green, Eosine, Ethyl Violet, Erythrosine B, Methyl Green,Crystal Violet, Basic Fuchsine, Phenolphthalein, 1,3-diphenyl triazine,Alizarin Red S, Thymolphthalein, Methyl Violet 2B, Quinaldine Red, RoseBengale, Thymolsulfo-phthalein, Xylenol Blue, Methyl Orange, Orange IV,Diphenyl Thiocarbazone, 2,7-dichlorofluorescein, para-Methyl Red, CongoRed, Benzopurpurine 4B, α-Naphthyl Red, Nile Blue 2B, Nile Blue A,Phenacetaline, Methyl Violet, Malachite Green, para-Fuchsine, Oil Blue#603 (available from ORIENT Chemical Industries, Ltd.), Oil Pink #312(available from ORIENT Chemical Industries, Ltd.), Oil Red 5B (availablefrom ORIENT Chemical Industries, Ltd.), Oil Scarlet #308 (available fromORIENT Chemical Industries, Ltd.), Oil Red OG (available from ORIENTChemical Industries, Ltd.), Oil Red RR (available from ORIENT ChemicalIndustries, Ltd.), Oil Green #502 (available from ORIENT ChemicalIndustries, Ltd.), Spiron Red BEH Special (available from HodogayaChemical Co., Ltd.), Victoria Pure Blue BOH (available from HodogayaChemical Co., Ltd.), Patent Pure Blue (available from Sumitomo MikuniChemical Industries, Ltd.), Sudan Blue II (available from BASF Company),m-Cresol Purple, Cresol Red, Rhodamine B, Rhodamine 6G, Fast Acid VioletR, Sulfo-rhodamine B, Auramine, 4-p-diethylaminophenylimino-naphthoquinone, 2-carboxyanilino-4-p-diethylaminophenylimino-naphthoquinone,2-carbostearylamino-4-p-dihydrooxyethyl-amino-phenylimino-naphthoquinone, p-methoxybenzoyl-p′-diethylamino-o′-methylphenylimino-acetanilide, cyano-p-diethylaminophenyl imino-acetanilide,1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone and1-β-naphthyl-4-p-diethylaminophenylimino-5-pyrazolone.

Particularly preferred organic dyes are triaryl-methane type dyes. Amongthese triaryl-methane type dyes, particularly useful ones are thosecontaining ions derived from sulfonic acid compounds as counter anions,as disclosed in, for instance, J.P. KOKAI No. Sho 62-2932471 andJapanese Patent Application Serial No. Hei 4-112844. These dyes may beused alone or in any combination and the added amount thereof preferablyranges from 0.3 to 15% by weight on the basis of the total weight of thelight-sensitive resin composition. Moreover, these dyes may, ifnecessary, be used in combination with other dyes and/or pigments andthe amount thereof used is not more than 70% by weight and morepreferably not more than 50% by weight on the basis of the total weightof the dyes and pigments.

The light-sensitive resin composition of the present invention can beused in the light-sensitive layer of a photopolymerizable printing plateas a negative printing plate. Such a light-sensitive resin compositionwill hereunder be described in detail. The principal components of thelight-sensitive resin composition of the present invention, which is aphotopolymerizable light-sensitive resin composition are, for instance,a compound containing an addition polymerizable ethylenicallyunsaturated double bond and a photopolymerization initiator, in additionto the foregoing fluorine atom-containing polymer and compounds such asa heat-polymerization inhibitor are, if necessary, added to the resincomposition.

The compound containing an addition polymerizable double bond mayarbitrarily be selected from compounds having at least one, preferablyat least two terminal ethylenically unsaturated double bonds. Examplesthereof are those having chemical structures such as monomers,prepolymers, i.e., dimmers, trimers and oligomers, or mixtures orcopolymers thereof. Examples of such monomers and copolymers thereof areesters of unsaturated carboxylic acids (such as acrylic acid,methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid andmaleic acid) with aliphatic polyhydric alcohol compounds and amides ofunsaturated carboxylic acids with aliphatic polyvalent amine compounds.

Examples of the monomers used in the esters of unsaturated carboxylicacids with aliphatic polyhydric alcohol compounds include acrylic acidesters, methacrylic acid esters, itaconic acid esters and crotonic acidesters. Specific examples of acrylic acid esters are ethylene glycoldiacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate,tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentylglycol diacrylate, trimethylolpropane triacrylate, trimethylolpropanetri(acryloyloxy-propyl)ether, trimethylolethane triacrylate, hexanedioldiacrylate, 1,4-cyclohexanediol diacrylate, tetraethylene glycoldiacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate,pentaerythritol tetraacrylate, dipentaerythritol diacrylate,dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate,sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate,sorbitol hexaacrylate, tri(acryloyloxy-ethyl)isocyanurate and polyesteracrylate oligomers.

Specific examples of methacrylic acid esters are tetramethylene glycoldimethacrylate, triethylene glycol dimethacrylate, neopentyl glycoldimethacrylate, trimethylolpropane trimethacrylate, trimethylolethanetrimethacrylate, ethylene glycol dimethacrylate, 1,3-butanedioldimethacrylate, hexanediol dimethacrylate, pentaerythritoldimethacrylate, pentaerythritol trimethacrylate, pentaerythritoltetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritolhexamethacrylate, dipentaerythritol pentamethacrylate, sorbitolmethacrylate, sorbitol tetramethacrylate,bis-[p-(3-methacryloxy-2-hydroxypropoxy)phenyl]dimethylmethane andbis-[p-(methacryloxy-ethoxy)phenyl]dimethylmethane.

Examples of itaconic acid esters are ethylene glycol diitaconate,propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanedioldiitaconate, tetramethylene glycol diitaconate, pentaerythritoldiitaconate and sorbitol tetraitaconate.

Examples of crotonic acid esters are ethylene glycol dicrotonate,tetramethylene glycol dicrotonate, pentaerythritol dicrotonate andsorbitol tetracrotonate. Examples of isocrotonic acid esters areethylene glycol diisocrotonate, pentaerythritol diisocrotonate andsorbitol tetraisocrotonate. Examples of maleic acid esters includeethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritoldimaleate and sorbitol tetramaleate. Moreover, mixtures of the foregoingester monomers may likewise be used.

Moreover, specific examples of amide monomers of unsaturated carboxylicacids with aliphatic polyvalent amine compounds includemethylene-bis-acryalmide, methylene-bis-methacrylamide,1,6-hexamethylene-bis-acrylamide, 1,6-hexamethylene-bis-methacrylamide,diethylenetriamine-trisacrylamide, xylylene-bis-acrylamide andxylylene-bis-methacrylamide. Examples thereof further include vinylurethane compounds having, in the molecule, at least two polymerizablevinyl groups, obtained by adding hydroxyl group-containing vinylmonomers represented by the following general formula (i) topolyisocyanate compounds having at least two isocyanate groups in themolecule, such as those disclosed in J.P. KOKOKU No. Sho 48-41708:

CH₂═C(R⁵)COOCH₂CH(R⁶)OH  (i)

Wherein R⁵ and R⁶ each represents H or a CH₃ group.

Examples thereof further include urethane acrylates disclosed in J.P.KOKAI No. Sho 51-37193; polyester acrylates disclosed in J.P. KOKAI No.Sho 48-64183 and J.P. KOKOKU Nos. Sho 49-43191 and Sho 52-30490; andpolyfunctional acrylates and methacrylates such as epoxy acrylatesobtained through the reactions of epoxy resins with (meth)acrylic acids.Moreover, usable herein also include those introduced as photohardenablemonomers and oligomers in Bulletin of Adhesives Association in Japan,1984, Vol. 20, No. 7, pp. 300-308.

In this respect, the amount of these double bond-containing compoundsranges from 5 to 70% by weight and preferably 10 to 50% by weight.

The photopolymerizable light-sensitive resin composition used in thepresent invention may comprise, as the photopolymerization initiator, avariety of photopolymerization initiators known in patents andliteratures or combined systems (photopolymerization initiator systems)containing at least two photopolymerization initiators, which areappropriately selected depending on the wavelength of the light raysemitted from a light source used. For instance, when using a lightsource emitting light rays having a wavelength in the proximity to 400nm, benzyl, benzoin ether, Michler's ketones, anthraquinone,thioxanthone, acridine, phenazine and benzophenone have been widelyused.

Moreover, if using visible light rays of not less than 400 nm, an Arlaser, secondary higher harmonic waves of semiconductor lasers, SHG-YAGlaser as light sources, there have also been proposed a variety ofphotopolymerization initiators. Examples thereof include certain kindsof photo-reducing dyes disclosed in U.S. Pat. No. 2,850,445 such as RoseBengale, Eosine and Erythrosine, or systems containing dyes andphotopolymerization initiators such as combined initiator systemscomprising dyes and amines (J.P. KOKOKU No. Sho 44-20189), combinedsystems comprising hexaaryl-biimidazole, radical generators and dyes(J.P. KOKOKU No. Sho 45-37377), hexaaryl-biimidazole-p-dialkylamino-benzylidene ketone systems (J.P. KOKOKU No. Sho 47-2528 and J.P.KOKAI No. Sho 54-155292), systems comprising cyclic cis-α-dicarbonylcompounds and dyes (J.P. KOKAI No. Sho 48-84183), cyclictriazine-merocyanine dye systems (J.P. KOKAI No. Sho 54-151024),3-ketocumarin-activator systems (J.P. KOKAI Nos. Sho 52-112681 and Sho58-15503), biimidazole-styrene derivative-thiol systems (J.P. KOKAI No.Sho 59-140203), organic peroxide-dye systems (J.P. KOKAI Nos. Sho59-1504, Sho 59-140203, Sho 59-189340 and Sho 62-174203, J.P. KOKOKU No.Sho 62-1641 and U.S. Pat. No. 4,766,055), dye-active halogen-containingcompound systems (for instance, J.P. KOKAI Nos. Sho 63-258903 and Hei2-63054), dye-borate compound systems (for instance, J.P. KOKAI Nos. Sho62-143044, Sho 62-150242, Sho 64-13140, Sho 64-13141, Sho 64-13142, Sho64-13143, Sho 64-13144, Sho 64-17048, Hei 1-229003, Hei 1-298348 and Hei1-138204), rhodanine ring-containing dye-radical generator systems (J.P.KOKAI Nos. Hei 2-179643 and Hei 2-244050), systems comprising titanoceneand 3-ketocumarin dyes (J.P. KOKAI No. Sho 63-221110), systemscomprising combinations of titanocene, Xanthene dyes and additionpolymerizable ethylenically unsaturated compounds containing amino orurethane groups (J.P. KOKAI Nos. Hei 4-221958 and Hei 4-219756), systemstitanocene and specific merocyanine dyes (J.P. KOKAI No. Hei 6-295061)and titanocene-benzopyran ring-containing dyes (J.P. KOKAI No. Hei8-334897). The amount of these photopolymerization initiators to be usedranges from 0.05 to 100 parts by weight, preferably 0.1 to 70 parts byweight and more preferably 0.2 to 50 parts by weight per 100 parts byweight of the ethylenically unsaturated compound.

Moreover, in the photopolymerizable light-sensitive resin compositionused in the present invention, it is desirable to incorporate, into theresin composition, a small amount of heat polymerization-inhibitoryagent for the prevention of any undesirable heat polymerization of thepolymerizable ethylenically unsaturated compound during the preparationof the resin composition or during the storage thereof, in addition tothe foregoing basic components. Examples of heatpolymerization-inhibitory agents suitably used herein are hydroquinone,p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol,benzoquinone, 4,4′-thiobis(3-methyl-6-t-butylphenol), 2,2′-methylenebis(4-methyl-6-t-butylphenol), N-nitrosophenyl-hydroxylamine cerous saltand N-nitrosophenyl-hydroxylamine aluminum salt. The amount of the heatpolymerization-inhibitory agent to be added preferably ranges from about0.01 to about 5% by weight on the basis of the total solid content ofthe resin composition. Moreover, it is also possible to, if necessary,incorporate, for instance, higher fatty acid derivatives such as behenicacid or behenic acid amide into the resin composition and to allow thederivatives to localize on the surface of the light-sensitive layerduring the drying process after the application thereof for theprevention of any polymerization due to oxygen. The amount of the higherfatty acid derivatives preferably ranges from about 0.5 to about 10% byweight on the basis of the total solid content of the resin composition.

The lithographic printing plate whose light-sensitive layer(image-forming layer) is prepared using a photopolymerizablelight-sensitive resin composition of the present invention may comprisea protective layer having oxygen barrier properties and formed on thelight-sensitive layer, for preventing the occurrence of anypolymerization due to oxygen. The protective layer having oxygen barrierproperties comprises a water-soluble vinyl polymer and examples of suchvinyl polymers include polyvinyl alcohol and partial esters thereof, andcopolymers of ethers and acetal, or a substantial amount of unsaturatedvinyl alcohol units required for imparting water-solubility to theresulting copolymer. Specific examples of polyvinyl alcohols are thosewhich are hydrolyzed to a rate of 71 to 100% and which have a degree ofpolymerization ranging from 300 to 2400.

Examples of commercially available water-soluble vinyl polymers includePVA-105, PVA-110, PVA-17, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS,PVA-CST, PVA-HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220,PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA-420,PVA-613 and L-8 available from Kuraray Co., Ltd. Examples of theforegoing copolymers are polyvinyl acetate chloroacetate or propionate,which is hydrolyzed to a rate ranging from 88 to 100%, polyvinyl formaland polyvinyl acetal as well as copolymers thereof. Examples of otheruseful polymers are polyvinyl pyrrolidone, gelatin and gum arabic, whichmay be used alone or in any combination.

The solvent used when applying the protective layer having oxygenbarrier properties in the present invention is preferably water, but maybe a mixture of pure water and an alcohol such as methanol or ethanol,or a ketone such as acetone or methyl ethyl ketone. In this respect, theconcentration of solid contents present in the coating solution suitablyranges from 1 to 20% by weight. In the present invention, the protectivelayer having oxygen barrier properties may further comprise a surfactantfor the improvement of the coating properties of the resulting solutionand/or a known additive such as a water-soluble plasticizer for theimprovement of physical properties of the resulting film. Examples ofsuch water-soluble plasticizers include propionamide, cyclohexane-diol,glycerin and sorbitol. Alternatively, for instance, a water-soluble(meth) acrylic polymer may likewise be incorporated into the coatingsolution. The coated amount of the protective layer having oxygenbarrier properties suitably ranges from about 0.1/m² to about 15/m² andmore preferably 1.0/m² to about 5.0/m² as expressed in terms of theweight thereof weighed after drying.

The present invention may likewise be applied to, for instance,lithographic printing plates of the following types, in addition to thepresensitized plate for making positive lithographic printing plates(also referred to as “positive PS plates”) whose light-sensitive layercomprises the foregoing positive light-sensitive resin compositionprepared using a quinonediazide, or a compound having alkaline-solublegroups protected by acid-decomposable groups and negative PS plates,which make use of photopolymerizable systems:

(1) Negative lithographic printing plate materials whose light-sensitivelayer comprises a diazo resin;

(2) Negative lithographic printing plate materials whose light-sensitivelayer comprises a photo-cross-linkable resin;

(3) Negative laser-direct printing type lithographic printing materialswhose light-sensitive layer comprises an alkali-soluble binder,acid-generator and acid (or heat)-cross-linkable compound;

(4) Positive laser-direct printing type lithographic printing materialswhose light-sensitive layer comprises a light-heat conversion agent, analkali-soluble binder and, as an optional component, a heat-decomposablesubstance, which can substantially reduce the solubility of the binderwhen it is in the undecomposed state; and

(5) Negative laser-direct printing type lithographic printing materialswhose light-sensitive layer comprises a light-heat conversion agent, athermally radical-generating agent and a radical polymerizable compound.

Components used in each lithographic printing plate material will inorder be detailed below.

The diazo resins used in the material (1) include, for instance, thoserepresented by salts of condensates of diazo-diarylamine with activecarbonyl compounds and preferred are those, which are light-sensitive,water-insoluble and organic solvent-soluble.

Examples of diazo resins particularly suitably used herein are organicacid salts or inorganic acid salts of condensates of, for instance,4-diazo-diphenylamine, 4-diazo-3-methyl-diphenylamine,4-diazo-4′-methyldiphenylamine, 4-diazo-3′-methyldiphenyl-amine,4-diazo-4′-methoxydiphenylamine, 4-diazo-3-methyl-4′-ethoxydiphenylamineor 4-diazo-3-methoxydiphenylamine with, for instance, formaldehyde,para-formaldehyde, acetaldehyde, benzaldehyde or4,4′-bis-methoxymethyl-diphenyl ether.

Examples of organic acids used for preparing such organic acid salts aremethanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid,xylenesulfonic acid, mesitylenesulfonic acid, dodecylbenzenesulfonicacid, naphthalenesulfonic acid, propionaphthalenesulfonic acid,1-naphthol-5-sulfonic acid, 2-nitrobenzenesulfonic acid,3-chlorobenzenesulfonic acid and2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, and examples ofinorganic acids used for preparing the foregoing inorganic acid saltsare hexafluoro-phosphoric acid, tetrafluoro-boric acid and thiocyanicacid. The diazo resins also usable in the present invention include, forinstance, diazo resins whose principal chain comprises polyester unitsas disclosed in J.P. KOKAI No. Sho 54-30121; diazo resins obtainedthrough reactions of carboxylic acid anhydride residue-containingpolymers with hydroxyl group-containing diazo compounds such as thosedisclosed in J.P. KOKAI No. Sho 61-273538; and diazo resins obtainedthrough reactions of polyisocyanate compounds with hydroxylgroup-containing diazo compounds.

The amount of these diazo resins used preferably ranges from 0 to 40% byweight on the basis of the total solid content of the resin compositionand at least two diazo resins may, if necessary, be used in combination.Moreover, when preparing a negative light-sensitive resin composition,an organic high molecular weight binder is in general used incombination. Examples of such organic high molecular weight bindersusable herein include acrylic resins, polyamide resins, polyesterresins, epoxy resins, polyacetal resins, polystyrene resins and novolakresins. Furthermore, the resin composition used in the present inventionmay comprise known additives for improving the quality of the resultingfilm such as heat polymerization-inhibitory agent, a dye, a pigment, aplasticizer and/or a stability-improving agent.

Examples of suitably used dyes are basic oil-soluble dyes such asCrystal Violet, Malachite Green, Victoria Blue, Methylene Blue, EthylViolet and Rhodamine B. Examples of commercially available dyes are“Victoria Pure Blue BOH” (available from Hodogaya Chemical Co., Ltd.)and “Oil Blue #603” (available from Orient Chemical Industry Co., Ltd.).Examples of pigments usable herein are Phthalocyanine Blue,Phthalocyanine Green, Dioxazine Violet and Quinacridone Red.

Examples of plasticizers are diethyl phthalate, dibutyl phthalate,dioctyl phthalate, tributyl phosphate, trioctyl phosphate, tricresylphosphate, tri(2-chloroethyl) phosphate and tributyl citrate. Moreover,examples of known stability-improving agents, which may simultaneouslybe used in the resin composition, are phosphoric acid, phosphorous acid,oxalic acid, tartaric acid, malic acid, citric acid, dipicolinic acid,polyacrylic acid, benzenesulfonic acid and toluenesulfonic acid. Theamount of these various kinds of additives to be added may varydepending on the purposes, but preferably ranges from 0 to 30% by weighton the basis of the total solid content of the light-sensitive resincomposition.

The photo-cross-linkable resin used in the material (2) is preferablyone having an affinity for an aqueous alkali developer and examplesthereof include copolymers containing cinnamic acid residues andcarboxyl groups as disclosed in J.P. KOKOKU No. Sho 54-15711; polyesterresins containing phenylene diacrylic acid residues and carboxyl groupsas disclosed in J.P. KOKAI No. Sho 60-165646; polyester resinscontaining phenylene diacrylic acid residues and phenolic hydroxylgroups as disclosed in J.P. KOKAI No. Sho 60-203630; polyester resinscontaining phenylene diacrylic acid residues and sodium imino-disulfonylgroups as disclosed in J.P. KOKOKU No. Sho 57-42858; polymers having, onside chains, azido groups and carboxyl groups as disclosed in J.P. KOKAINo. Sho 59-208552; and polymers having, on side chains, maleimido groupsas disclosed in J.P. KOKAI No. Hei 7-295212.

The alkali-soluble binders and acid-generating agents used in thematerial (3) may be the same as those used in the aforementionedpositive PS plate, which makes use of the quinonediazide or the compoundhaving alkali-soluble groups protected with acid-decomposable groups.The term “acid (or heat)-cross-linkable compound” herein used means acompound capable of undergoing crosslinking in the presence of an acidand examples thereof include aromatic and heterocyclic compoundsmulti-substituted with hydroxymethyl groups, acetoxymethyl groups oralkoxymethyl groups, with compounds obtained by condensing phenols andaldehydes under basic conditions being particularly preferred. Among theforegoing compounds, preferred are, for instance, compounds obtained bycondensing phenols with formaldehyde under basic conditions as describedabove; compounds obtained from m-cresol and formaldehyde, compoundsprepared from bisphenol A and formaldehyde and compounds obtained from4,4′-bisphenol and formaldehyde, according to the same procedures usedabove; and other compounds such as those disclosed in G.B. Patent No.2,082,339 as resol resins.

These acid-cross-linkable compounds preferably have a weight averagemolecular weight ranging from 500 to 100,000 and a number averagemolecular weight ranging from 200 to 50,000. Examples of other compoundspreferably used herein likewise include aromatic compounds replaced withalkoxymethyl or oxiranylmethyl groups disclosed in EP-A-0,212,482;monomers and oligomers such as melamine-formaldehyde condensate andurea-formaldehyde condensate disclosed in EP-A-0,133,216, DE-A-3,634,671and DE 3,711,264; and alkoxy-substituted compounds disclosed inEP-A-0,212,482. Examples of other preferred compounds includemelamine-formaldehyde derivatives carrying at least two freeN-hydroxymethyl, N-alkoxymethyl or N-acyloxymethyl groups. Among them,particularly preferred are N-alkoxymethyl derivatives.

In addition, low molecular weight or oligomeric silanols may be used assilicon atom-containing crosslinking agents. Examples thereof aredimethyl- and diphenyl-silane-diol and preliminarily condensed oligomershaving units derived from these diols and usable herein include, forinstance, those disclosed in EP-A-0,377,155. Among the aromatic andheterocyclic compounds multi-substituted with alkoxymethyl groups,preferred are compounds whose alkoxymethyl groups are present atpositions adjacent to hydroxyl groups and in which the alkoxymethylgroups each has not more than 18 carbon atoms, with the compoundsrepresented by the following general formulas (ii) to (v) beingparticularly preferred:

Wherein L₁ to L₈ may be the same or different and each represents analkoxymethyl group substituted with an alkoxy group having not more than18 carbon atoms such as a methoxymethyl or ethoxymethyl group. Thesecompounds are preferred since they have high crosslinking efficiency andpermit the improvement of the printing durability of the resultingprinting plate. The foregoing thermally cross-linkable compounds may beused alone or in any combination of at least two of them.

The acid-cross-linkable compound used in the present invention is usedin the light-sensitive layer in an amount ranging from 5 to 80% byweight, preferably 10 to 75% by weight and particularly preferably 20 to70% by weight on the basis of the total solid content of thelight-sensitive layer. This is because if the added amount of theacid-cross-linkable compound is less than 5% by weight, the resultinglight-sensitive layer of the lithographic printing plate material isinsufficient in the durability, while if it exceeds 80% by weight, thestability of the light-sensitive layer during storage is insufficient.

The alkali-soluble binders used in the material (4) may be the same asthose used in the aforementioned positive PS plate, which makes use ofthe aforementioned quinonediazide. The substances, which areheat-decomposable and which can substantially reduce the solubility ofthe alkali-soluble binder in the undecomposed state, may, for instance,be a variety of onium salts and quinonediazide compounds. Thesecompounds are preferably used in the present invention, since they areexcellent in the effect of reducing the solubility of the alkali-solublebinder. Specific examples of such onium salts are diazonium salts,ammonium salts, phosphonium salts, iodonium salts, sulfonium salts,selenonium salts and arsonium salts.

Examples of onium salts preferably used in the present invention includediazonium salts disclosed in, for instance, S. I. Schlesinger, Photogr.Sci. Eng., 1974, 18:387, T. S. Bal et al., Polymer, 1980, 21:423 andJ.P. KOKAI No. Hei 5-158230; ammonium salts disclosed in, for instance,U.S. Pat. Nos. 4,069,055 and 4,069,056 and J.P. KOKAI No. Hei 3-140140;phosphonium salts disclosed in, for instance, D.C. Necker et al.,Macromolecules, 1984, 17:2468, C. S. Wen et al., Tech. Proc. Conf. Rad.Curing ASIA, 1988 (October), p. 478, Tokyo and U.S. Pat. Nos. 4,069,055and 4,069,056; iodonium salts disclosed in, for instance, J. V. Crivelloet al., Macromolecules, 1977, 10(6): 1307, Chem. & Eng. News, Nov. 28,1988, p. 31, European Patent No. 104,143, U.S. Pat. Nos. 339,049 and410,201 and J.P. KOKAI Nos. Hei 2-150848 and Hei 2-296514; sulfoniumsalts disclosed in, for instance, J. V. Crivello et al., Polymer J.,1985, 17:73, J. V. Crivello et al., J. Org. Chem., 1978, 43:3055, W. R.Watt et al., J. Polymer Sci., Polymer Chem. Ed., 1984, 22:1789, J. V.Crivello et al., Polymer Bull., 1985, 14:279, J. V. Crivello et al.,Macromolecules, 1981, 14(5):1141, J. V. Crivello et al., J. PolymerSci., Polymer Chem. Ed., 1979, 17:2877, European Patent Nos. 370,693,233,567, 297,443 and 297,442, U.S. Pat. Nos. 3,902,114, 4,933,377,410,201, 339,049, 4,760,013, 4,734,444 and 2,833,827 and German PatentNos. 2,904,626, 3,604,580 and 3,604,581; selenonium salts disclosed in,for instance, J. V. Crivello et al., Macromolecules, 1977, 10(6):1307and J. V. Crivello et al., J. Polymer Sci., Polymer Chem. Ed., 1979,17:1047; and arsonium salts disclosed in, for instance, C. S. Wen etal., Tech. Proc. Conf. Rad. Curing ASIA, 1988 (October), p. 478, Tokyo.

Among them, diazonium salts are particularly preferably used in thepresent invention. Moreover, particularly preferred diazonium salts arethose disclosed in J.P. KOKAI No. Hei 5-158230. Examples ofquinonediazide compounds preferably used herein are o-quinonediazidecompounds.

The o-quinonediazide compound used in the present invention is onehaving at least one o-quinonediazido group, whose alkali-solubilityincreases through thermal decomposition and may be those having avariety of structures. More specifically, o-quinonediazide loses itsability of controlling the solubility of the alkali-soluble binderthrough thermal decomposition, o-quinonediazide as such may be convertedinto an alkali-soluble substance and these two effects would assist inthe improvement of the solubility of the light-sensitive material. Theo-quinonediazide compounds usable in the present invention include, forinstance, those described in J. Corser, “Light-Sensitive Systems”, JohnWiley & Sons Inc., pp. 339-352, but particularly preferred are sulfonicacid esters or sulfonic acid amides of o-quinonediazide, which arereacted with a variety of aromatic polyhydroxy compounds or aromaticamino group-containing compounds. Moreover, preferably used herein alsoinclude esters of benzoquinone-(1,2)-diazide sulfonic acid chloride ornaphthoquinone-(1,2)-diazide-5-sulfonic acid chloride withpyrogallol-acetone resins as disclosed in J.P. KOKOKU No. Sho 43-28403and esters of benzoquinone-(1,2)-diazide sulfonic acid chloride ornaphthoquinone-(1,2)-diazide-5-sulfonic acid chloride withphenol-formaldehyde resins as disclosed in U.S. Pat. Nos. 3,046,120 and3,188,210.

Furthermore, suitably used herein also include esters ofnaphthoquinone-(1,2)-diazide-4-sulfonic acid chloride withphenol-formaldehyde resins or cresol-formaldehyde resins and esters ofnaphthoquinone-(1,2)-diazide-4-sulfonic acid chloride withpyrogallol-acetone resins. Examples of other useful o-quinonediazidecompounds have been known and reported in a variety of patent-relatedarticles (patent specifications) and there may be listed, for instance,those disclosed in, for instance, J.P. KOKAI Nos. Sho 47-5303, Sho48-63802, Sho 48-63803, Sho 48-96575, Sho 49-38701 and Sho 48-13354,J.P. KOKOKU Nos. Sho 41-11222, Sho 45-9610 and Sho 49-17481, U.S. Pat.Nos. 2,797,213, 3,454,400, 3,554,323, 3,573,917, 3,674,495 and3,785,825, G.B. Patent Nos. 1,277,602, 1,251,345, 1,267,005, 1,329,888and 1,330,932 and German Patent No. 854,890.

The amount of the o-quinonediazide compound used in the presentinvention preferably ranges from 1 to 50% by weight, more preferably 5to 30% by weight and more preferably 10 to 30% by weight on the basis ofthe total solid content of the lithographic printing plate material.These compounds may be used alone or a mixture containing at least twoof these compounds. This is because if the added amount of theo-quinonediazide compound is less than 1% by weight, the image-recordingproperties of the resulting printing plate material is impaired, whileif it exceeds 50% by weight, the durability of the image area isdeteriorated and/or the sensitivity of the material is reduced.

Examples of counterions for the onium salts suitably used herein arethose derived from tetrafluoro-boric acid, hexafluoro-phosphoric acid,triisopropyl-naphthalene-sulfonic acid, 5-nitro-o-toluene-sulfonic acid,5-sulfosalicylic acid, 2,5-dimethylbenzene-sulfonic acid,2,4,6-trimethylbenzene-sulfonic acid, 2-nitrobenzene-sulfonic acid,3-chlorobenzene-sulfonic acid, 3-bromobenzene-sulfonic acid,2-fluorocapryl-naphthalene-sulfonic acid, dodecylbenzene-sulfonic acid,1-naphthol-5-sulfonic acid,2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid andp-toluene-sulfonic acid. Among these counterions, particularly preferredare those derived from alkyl-aromatic sulfonic acids such ashexafluoro-phosphoric acid, triisopropyl-naphthalene-sulfonic acid and2,5-dimethylbenzene-sulfonic acid. The added amount of the foregoingadditives other than the o-quinonediazide compounds preferably rangesfrom 1 to 50% by weight, more preferably 5 to 30% by weight andparticularly preferably 10 to 30% by weight on the basis of the totalsolid content of the lithographic printing plate material.

Specific examples of ingredients used in the material (5) may be thesame as those listed above in connection with the foregoingphotopolymerizable system. Most of the photopolymerization initiatorsmay likewise be useful as thermally radical-generating agents. Moreover,substances such as azobis compounds (azobis-isobutyronitrile) anddiazonium compounds may likewise be used as heat-polymerizationinitiators. The addition-polymerizable compounds are likewise in commonwith those used in the photopolymerizable system. In this case, thelight-heat conversion agent may be any one inasmuch as it may absorb thelight emitted from a light source used for the imagewise exposure andtherefore, all of the dyes listed above in connection with thephotopolymerizable system can be used in this case. In this respect,however, the practically used high power laser beam source for the heatmode exposure is mainly a (near) infrared light source emitting a lightbeam of not less than 750 nm and therefore, the most useful light-heatconversion agent at present is a compound capable of absorbing the(near) infrared light rays. A variety of IR absorbing agents arecommercially available, but most preferably used herein are, forinstance, hepta-methine cyanine dyes, phthalocyanine dyes and carbonblack.

Incidentally, the light-sensitive resin composition used in the presentinvention may further comprise various kinds of additives depending on avariety of purposes, for instance, various kinds of hydrophobicgroup-containing resins such as octylphenol-formaldehyde resins,t-butylphenol-formaldehyde resins, t-butylphenol-benzaldehyde resins,rosin-modified novolak resins and o-naphthoquinonediazide-sulfonic acidesters of these modified novolak resins for the improvement of theink-receptivity of images and plasticizers such as dibutyl phthalate,dioctyl phthalate, butyl glycolate, tricresyl phosphate and dioctyladipates for the improvement of the flexibility of the resulting film.The added amount of these additives preferably ranges from 0.01 to 30%by weight on the basis of the total solid content of the resincomposition.

In addition, these resin composition may further comprise known resinsfor the further improvement of the wear resistance of the resultingfilm. Examples of such resins usable herein are polyvinyl acetal resins,polyurethane resins, epoxy resins, vinyl chloride resins, nylons,polyester resins and acrylic resins, which may be used alone or in anycombination. The amount thereof to be incorporated into the resincomposition preferably ranges from 2 to 40% by weight on the basis ofthe total solid content of the resin composition.

Moreover, the light-sensitive resin composition used in the presentinvention may comprise nonionic surfactants such as those disclosed in,for instance, J.P. KOKAI Nos. Sho 62-251740 and Hei 4-68355 and/oramphoteric surfactants such as those disclosed in, for instance, J.P.KOKAI Nos. Sho 59-121044 and Hei 4-13149, for expanding the developmentlatitude. Specific examples of such nonionic surfactants are sorbitantristearate, sorbitan mono-palmitate, sorbitan trioleate, stearic acidmonoglyceride, polyoxyethylene sorbitan monooleate and polyoxyethylenenonylphenyl ether, while specific examples of such amphotericsurfactants include alkyl-di(aminoethyl) glycine, alkyl-polyaminoethylglycine hydrochloride, AMOGEN K (the trade name of anN-tetradecyl-N,N-betaine type surfactant commercially available fromDai-ichi Kogyo Seiyaku Co., Ltd.), 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and REBON 15 (the trade name of analkyl-imidazoline type surfactant commercially available from SanyoChemical Industries, Ltd.). The rate of the light-sensitive resincomposition occupied by these nonionic and/or amphoteric surfactantspreferably ranges from 0.05 to 15% by weight and more preferably 0.1 to5% by weight on the basis of the total solid content of the composition.

Improvement of Surface Quality of Coated Film: The light-sensitive resincomposition used in the present invention may comprise a surfactant forthe improvement of the surface quality of the coated film such asfluorine atom-containing surfactants as disclosed in J.P. KOKAI No. Sho62-170950. The added amount thereof preferably ranges from 0.001 to 1.0%by weight and more preferably 0.005 to 0.5% by weight on the basis ofthe total amount of the light-sensitive resin composition (total solidcontent).

In addition, the light-sensitive resin composition used in the presentinvention may comprise a dye of yellow color, preferably one whoseabsorbance observed at 436 nm is not less than 70% of that observed at417 nm.

When preparing a lithographic printing plate material from thelight-sensitive resin composition comprising a fluorine-containingpolymer, the composition is applied onto the surface of a substrate as alight-sensitive layer. More specifically, the light-sensitive resincomposition comprising a fluorine-containing polymer is dissolved ordispersed in a solvent comprising at least one member selected from thefollowing organic solvents, followed by the application thereof to thesurface of a substrate and then drying. Such an organic solvent may beany known and currently used one, but may be selected from those havinga boiling point ranging from 40 to 200° C., in particular, 60 to 160° C.from the viewpoint of advantages observed upon drying. In this respect,it is a matter of course that the solvent is selected from those capableof dissolving the fluorine-containing polymer used in the invention.

Specific examples of organic solvents are alcohols such as methylalcohol, ethyl alcohol, n- or iso-propyl alcohol, n- or iso-butylalcohol and diacetone alcohol; ketones such as acetone, methyl ethylketone, methyl propyl ketone, methyl butyl ketone, methyl amyl ketone,methyl hexyl ketone, diethyl ketone, di-isobutyl ketone, cyclohexanone,methyl cyclohexanone and acetyl acetone; hydrocarbons such as benzene,toluene, xylene, cyclohexane and methoxy benzene; acetic acid esterssuch as ethyl acetate, n- or iso-propyl acetate, n- or iso-butylacetate, ethylbutyl acetate and hexyl acetate; halides such as methylenedichloride, ethylene dichloride and monochloro-benzene; ethers such asisopropyl ether, n-butyl ether, dioxane, dimethyl dioxane andtetrahydrofuran; polyhydric alcohols and derivatives thereof such asethylene glycol, methyl cellosolve, methyl cellosolve acetate, ethylcellosolve, diethyl cellosolve, cellosolve acetate, butyl cellosolve,butyl cellosolve acetate, methoxy-methoxy ethanol, diethylene glycolmonomethyl ether, diethylene glycol dimethyl ether, diethylene glycolmethylethyl ether, diethylene glycol diethyl ether, propylene glycol,propylene glycol monomethyl ether, propylene glycol monomethyl etheracetate, propylene glycol monoethyl ether, propylene glycol monoethylether acetate, propylene glycol monobutyl ether and 3-methyl-3-methoxybutanol; and special solvents such as dimethylsulfoxide andN,N-dimethyl-formamide, which may suitably be used alone or in anycombination. The concentration of the solid contents present in theresin composition to be applied suitably ranges from 2 to 50% by weight.

The method for coating the resin composition used in the presentinvention may be, for instance, roll coating, dip coating, air-knifecoating, gravure coating, gravure-offset coating, hopper coating, bladecoating, wire-doctor coating and spray coating techniques and the amountof the composition to be coated preferably ranges from 0.3 to 4.0 g/m²as expressed in terms of the weight weighed after drying. The smallerthe coated amount of the composition, the smaller the quantity ofexposed light for obtaining images, but the strength of the resultingfilm is reduced. On the other hand, the higher the amount of thecomposition to be coated, the higher the quantity of exposed light forobtaining images, but the strength of the light-sensitive filmincreases. For instance, when the resulting material is used as aprinting plate, the latter would provide an increased number ofacceptable printed matters (in other words, the printing plate has ahigh printing durability).

The drying of the light-sensitive resin composition applied onto thesubstrate is in general conducted using heated air. The temperature ofthe heated air suitably ranges from 30 to 200° C., in particular, 40 to140° C. The drying temperature may be maintained at a constant level ormay stepwise be increased. In some cases, good results would be obtainedby removing any humidity in the air for drying. The heated air ispreferably supplied to the coated surface at a rate ranging from 0.1m/sec to 30 m/sec, in particular, 0.5 to 20 m/sec.

Matting Layer: A matting layer is preferably formed on the surface ofthe light-sensitive layer applied according to the foregoing method forreducing the time required for the evacuation upon contact exposureusing a vacuum printing frame and for the prevention of the formation ofany indistinct image during printing. More specifically, the mattinglayer can be formed by, for instance, a method as disclosed in J.P.KOKAI No. Sho 50-125805 and J.P. KOKOKU No. Sho 57-6582 or a method inwhich solid powder is thermally fusion-bonded to the surface asdisclosed in J.P. KOKOKU No. Sho 62-62337.

The substrate used in, for instance, lithographic printing plate is adimensionally stable plate-like material and preferably used hereininclude those conventionally used as substrates for printing plates.Examples of such substrates include paper; paper laminated with aplastic film (such as polyethylene, polypropylene or polystyrene film);metal plates of, for instance, aluminum (including alloys thereof),zinc, iron and copper; plastic films of, for instance, cellulosediacetate, cellulose triacetate, cellulose propionate, cellulosebutyrate, cellulose butyrate acetate, cellulose nitrate, polyethyleneterephthalate, polyethylene, polystyrene, polypropylene, polycarbonateand polyvinyl acetal; and paper or plastic films on which the foregoingmetals are deposited or paper or plastic films laminated with foils ofthe foregoing metals, with aluminum plates being particularly preferredas the substrates for the lithographic printing plate. Examples ofaluminum plates include pure aluminum plate and aluminum alloy plates. Avariety of aluminum alloys may be used herein and examples thereof arethose of aluminum with other metal such as silicon, copper, manganese,magnesium, chromium, zinc, lead, bismuth and/or nickel. These alloyscomprise a negligible amount of impurities in addition to minor amountsof iron and titanium.

The substrate is if necessary subjected to a surface treatment. Forinstance, in case of light-sensitive lithographic printing plate, thesurface of the substrate used is hydrophilized. Moreover, when thesubstrate has a metal, in particular, aluminum surface, the substrate ispreferably subjected to a surface-treatment such as a grainingtreatment, a treatment of dipping the same in an aqueous solution of,for instance, sodium silicate, potassium fluorozirconate or a phosphoricacid salt, or an anodization treatment. Preferably used herein alsoinclude, for instance, an aluminum plate, which is grained and thentreated by dipping in an aqueous solution of sodium silicate asdisclosed in U.S. Pat. No. 2,714,066 and an aluminum plate, which issubjected to an anodization treatment and then a treatment of dippingthe anodized plate in an aqueous solution of an alkali metal silicate asdisclosed in U.S. Pat. No. 3,181,461. The foregoing anodizationtreatment is carried out by passing an electric current through a systemin which the aluminum plate serves as an anode in an electrolyteselected from the group consisting of aqueous or non-aqueous solutionsof, for instance, inorganic acids such as phosphoric acid, chromic acid,sulfuric acid and boric acid or organic acids such as oxalic acid andsulfamic acid or salts thereof and mixtures of these aqueous ornon-aqueous solutions.

Moreover, the silicate electrodeposition as disclosed in U.S. Pat. No.3,658,662 is also effective as a surface treatment of the substrate. Thehydrophilization treatment is applied to the substrate not only formaking the surface thereof hydrophilic, but also for preventing theoccurrence of any harmful reaction with the light-sensitive resincomposition applied onto the substrate and for improving the adhesionbetween the light-sensitive layer and the substrate. Prior to thegraining of the aluminum plate, the surface thereof may, if necessary,be subjected to pre-treatments for the removal of the rolling oil on thesurface and for the exposure the clean aluminum surface. To remove therolling oil, there has been used, for instance, a solvent such astrichlene and a surfactant. In addition, to expose the clean aluminumsurface, there has widely been used a method, which makes use of analkali etching agent such as sodium hydroxide or potassium hydroxide.

Methods for graining effectively used herein include, for instance,mechanical, chemical and/or electrochemical methods. Examples of suchmechanical methods are ball-polishing methods, ball-polishing methods,blast-polishing methods and brush-polishing in which the substratesurface is rubbed with a nylon brush in the presence of an aqueousdispersion or slurry of an abrasive such as pumice stone, examples ofsuch chemical methods suitably used herein include those in which thesubstrate is dipped in a saturated aqueous solution of an aluminum saltof a mineral acid, as disclosed in J.P. KOKAI No. Sho 54-31187 andexamples of the foregoing electrochemical methods are those in which thesubstrate is electrolyzed in an acidic electrolyte such as thosecomprising hydrochloric acid, sulfuric acid or mixture thereof, using analternating current. Among these surface-roughening treatments, thesurface-roughening method comprising the combination of mechanical andelectrochemical surface-roughening treatments as disclosed in J.P. KOKAINo. Sho 55-137993 is preferably used herein since the ink-receptiveimages are strongly adhered to the substrate surface. The grainingaccording to the foregoing method is preferably carried out to such anextent that the centerline surface roughness (Ra) of the resultingaluminum plate falls within the range of from 0.3 to 1.0 μm. Thealuminum substrate thus surface-grained is, if necessary, subjected towater washing and chemical etching treatments.

The foregoing etching solution is in general selected from aqueoussolutions of bases or acids capable of dissolving aluminum. In thiscase, the etching solution should be one whose components never form anycoating film of other than aluminum. Examples of etching agentspreferably used herein are basic substances such as sodium hydroxide,potassium hydroxide, trisodium phosphate, disodium phosphate,tripotassium phosphate and dipotassium phosphate, and acidic substancessuch as sulfuric acid, persulfuric acid, phosphoric acid, hydrochloricacid and salts thereof. On the other hand, the use of salts of metals,whose ionization tendency is lower than that of aluminum such as zinc,chromium, cobalt, nickel and copper, is not preferred since they areliable to form unnecessary coating films on the film to be etched. Theconcentration of these etching agents and the setting of the etchingtemperature should most preferably be determined such that the rate ofdissolving aluminum or an alloy used falls within the range of from 0.3to 40 g/m² per unit (one minute) immersion time, but the rate ofdissolution may be beyond the range defined above.

The etching process may be conducted by, for instance, immersing analuminum plate in the foregoing etching solution or applying the etchingsolution onto the surface of an aluminum plate and the aluminum plate ispreferably treated with such an etching solution such that the amount ofaluminum removed through the etching ranges from 0.5 to 10 g/m². It isdesirable to use an aqueous solution of a base as the foregoing etchingagent since it can ensure a high etching rate. In this case, the etchingprocess is accompanied by the formation of smut and therefore, thealuminum plate is generally subjected to a de-smutting treatment afterthe etching. In this de-smutting treatment, an acid is in general usedand examples of such acids are nitric acid, sulfuric acid, phosphoricacid, chromic acid, hydrofluoric acid and hydrogen borofluoride. Thealuminum plate thus etched is, if necessary, washed with water and thenanodized. The anodization may be carried out according to the usualmethod currently used in this field. More specifically, a DC or ACcurrent is passed through the aluminum plate in an aqueous ornon-aqueous solution of sulfuric acid, phosphoric acid, chromic acid,oxalic acid, sulfamic acid, benzenesulfonic acid or a mixture of atleast two of them to thus form an anodized film on the aluminumsubstrate.

The conditions for the anodization variously vary depending on theelectrolyte used and therefore, cannot unconditionally be determined,but it is in general desirable that the electrolyte concentration rangesfrom 1 to 80% by weight, the temperature thereof ranges from 5 to 70°C., the current density used ranges from 0.5 to 60 A/dm², the electricvoltage to be applied ranges from 1 to 100 V and the electrolyzationtime ranges from 30 seconds to 50 minutes. Among these anodizationtreatments, particularly preferred are the methods disclosed in G.B.Patent No. 1,412,768 in which an aluminum plate is anodized at a highcurrent density in a sulfuric acid solution and the methods disclosed inU.S. Pat. No. 3,511,661 in which an aluminum plate is anodized using aphosphoric acid solution as the electrolyzation bath. The aluminum platethus surface-roughened and then anodized according to the foregoingmethods may if necessary be hydrophilized and preferred examples of suchhydrophilization treatments are methods comprising treating the samewith an alkali metal silicate such as an aqueous sodium silicatesolution disclosed in U.S. Pat. Nos. 2,714,066 and 3,181,461, withpotassium fluorozirconate as disclosed in J.P. KOKOKU No. Sho 36-22063and with polyvinyl phosphonic acid as disclosed in U.S. Pat. No.4,153,461.

Organic Undercoating Layer: In the light-sensitive lithographic printingplate according to the present invention, an organic undercoating layeris preferably applied onto the surface of a substrate prior to theapplication of a light-sensitive layer thereto for reducing thepossibility of remaining any light-sensitive layer on the non-imagearea. Examples of organic compounds used for forming such an organicundercoating layer are carboxymethyl cellulose, dextrin, gum arabic,amino group-containing phosphonic acids such as 2-aminoethyl-phosphonicacid, organic phosphonic acids, which may have a substituent, such asphenyl-phosphonic acid, naphthyl-phosphonic acid, alkyl-phosphonic acid,glycerophosphonic acid, methylene-diphosphonic acid andethylene-diphosphonic acid, organic phosphoric acids, which may have asubstituent, such as phenyl-phosphoric acid, naphthyl-phosphoric acid,alkyl-phosphoric acid and glycero-phosphoric acid, organic phosphinicacids, which may have a substituent, such as phenyl-phosphinic acid,naphthyl-phosphinic acid, alkyl-phosphinic acid and glycero-phosphinicacid, amino acids such as glycine and β-alanine, and hydrochlorides ofhydroxyl group-containing amines such as triethanolamine hydrochloride,which may be used alone or in any combination.

Alternatively, it is also possible to use at least one compound selectedfrom the group consisting of polymeric compounds having, in themolecule, structural units represented by, for instance, poly(p-vinylbenzoate). Specific examples thereof are copolymers of p-vinyl benzoatewith vinyl-benzyl-triethyl ammonium salts and copolymers of p-vinylbenzoate with vinyl-benzyl-triethyl ammonium chloride.

This organic undercoating layer can be applied to the surface of asubstrate according to the following method. More specifically, theorganic undercoating layer is, for instance, formed by a method, whichcomprises the steps of applying, onto the surface of an aluminum plate,a solution prepared by dissolving the foregoing organic compound inwater, an organic solvent such as methanol, ethanol or methyl ethylketone or mixture thereof and then drying; or a method, which comprisesthe steps of dipping an aluminum plate in a solution prepared bydissolving the foregoing organic compound in water, an organic solventsuch as methanol, ethanol or methyl ethyl ketone or mixture thereof tothus adsorb the organic compound on the aluminum plate, washing with,for instance, water and then drying. In the former method, the solutionof the foregoing organic compound having a concentration ranging from0.005 to 10% by weight can be applied to the aluminum plate according toa variety of methods such as bar coater coating, whirler coating, spraycoating or curtain coating technique. In the latter method, theconcentration of the solution ranges from 0.01 to 20% by weight,preferably 0.05 to 5% by weight, the dipping temperature ranges from 20to 90° C., preferably 25 to 50° C. and the dipping time ranges from 0.1second to 20 minutes and preferably 2 seconds to one minute.

The solution used for the application of an organic undercoating layermay comprise a basic substance such as ammonia, triethylamine, orpotassium hydroxide or an acidic substance such as hydrochloric acid orphosphoric acid to control the pH value of the solution and the pH valuethereof may fall within the range of from 1 to 12. Moreover, a yellowdye may be added to the solution for the improvement of the tonereproduction of the light-sensitive lithographic printing plate. Thesolution may further comprise a compound represented by the followinggeneral formula (a):

(OH)x-R⁷—(COOH)y  (a)

Wherein R⁷ represents a substituted or unsubstituted arylene grouphaving not more than 14 carbon atoms and x and y each independentlyrepresents an integer ranging from 1 to 3. Specific examples of theforegoing compounds represented by Formula (a) are 3-hydroxybenzoicacid, 4-hydroxybenzoic acid, salicylic acid, 1-hydroxy-2-naphthoic acid,2-hydroxy-1-naphthoic acid, 2-hydroxy-3-naphthoic acid,2,4-dihydroxybenzoic acid and 10-hydroxy-9-anthracenecarboxylic acid.The amount of the organic undercoating layer to be applied suitablyranges from 1 to 100 mg/m² and preferably 2 to 70 mg/m² as expressed interms of the amount weighed after drying. This is because if the coatedamount of the layer is less than 1 mg/m², the resulting printing platenever shows sufficient printing durability, while if it exceeds 100mg/m², the same result would be observed.

Back Coat: A back coat is if necessary formed on the back face of thesubstrate. Examples of such back coats preferably used herein are thosederived from organic polymer compounds as disclosed in J.P. KOKAI No.Hei 5-45885 and those comprising metal oxides obtained by hydrolyzingand polycondensing organic or inorganic metal compounds as disclosed inJ.P. KOKAI No. Hei 6-35174. Among these materials for forming thesecoated layers, particularly preferred are alkoxy compounds of siliconsuch as Si(OCH₃)₄, Si(OC₂H₅)₄, Si(OC₃H₇)₄ and Si(OC₄H₉)₄ since they arenot expensive and easily available and the coated layers of the metaloxides are excellent in the resistance to developers.

The lithographic printing plate material thus prepared is in generalimagewise exposed to light and then developed. As light sources foractinic light rays used for the imagewise exposure, there may be listed,for instance, a mercury lamp, a metal halide lamp, a xenon lamp, achemical lamp and a carbon arc lamp. Examples of radiant rays are anelectron beam, X-rays, an ion beam and far infrared rays. Usable hereinalso include g-radiations, I-radiations, Deep-UV light rays and ahigh-density energy beam (laser beam). Examples of laser beams are He—Nelaser, Ar laser, Kr laser, He—Cd laser and KrF excimer laser beams.Moreover, in case of the laser directly exposed type printing plate,preferably used light sources are those emitting light rays havingwavelengths falling within the range of from near infrared to infrared,with solid lasers and semiconductor lasers being particularly preferred.

Developers preferably used for developing the lithographic printingplate prepared using the light-sensitive resin composition of thepresent invention are, for instance, those comprising (a) at least onesaccharide selected from non-reducing saccharides and (b) at least onebase and having a pH value ranging from 9.0 to 13.5. The developer willhereunder be described in more detail. In this specification, the term“developer” used herein means both development-initiation liquid(developers in a narrow sense) and supplementary developers.

Preferably, this developer comprises at least one compound selected fromnon-reducing saccharides and at least one base as principal componentsand has a pH value ranging from 9.0 to 13.5. Such non-reducingsaccharides are saccharides, which do not have any free aldehyde and/orketone groups and do not accordingly show any reducing ability. They aredivided into trehalose-type oligosaccharides in which reducing groupsare linked together; glycosides in which reducing groups of saccharidesare bonded to non-saccharides; and sugar alcohols, which are obtained byreducing saccharides through hydrogenation. All of these three kinds ofnon-reducing saccharides can suitably be used in the present invention.Examples of trehalose-type oligosaccharides include saccharose andtrehalose; examples of glycosides are alkyl glycosides, phenolglycosides and mustard oil glycosides; and examples of sugar alcoholsare D,L-arabitol, ribitol, xylitol, D,L-sorbitol, D,L-mannitol,D,L-iditol, D,L-talitol, dulcitol and allo-dulcitol. Moreover, suitablyused herein include maltitol obtained by the hydrogenation ofdisaccharides and reduced derivatives obtained by the hydrogenation ofoligosaccharides (reduced starch syrup). Among these non-reducingsaccharides, particularly preferred are sugar alcohols and saccharose,with D-sorbitol, saccharose and reduced starch syrup being particularlypreferred because of their buffering effect in a moderate pH range andcheapness.

These non-reducing saccharides may be used alone or in any combinationof at least two of them and the rate of the developer occupied by thesenon-reducing saccharides preferably ranges from 0.1 to 30% by weight andmore preferably 1 to 20% by weight on the basis of the total weight ofthe developer.

If the amount of the non-reducing saccharide is less than the lowerlimit, any sufficient buffering effect of the non-reducing saccharide isnot expected at all, while if it exceeds the upper limit, it isdifficult to highly concentrate the resulting developer and theproduction cost thereof would be increased. When a reducing saccharideis used in combination with a base, the resulting developer undergoesbrowning with time and shows gradual reduction of the pH value thereof.Accordingly, the developer suffers from a problem such that thedeveloping ability is reduced.

The bases used in combination with the foregoing non-reducingsaccharides usable herein may be any conventionally known alkalineagents. Specific examples thereof include inorganic alkaline agents suchas sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodiumphosphate, tripotassium phosphate, triammonium phosphate, disodiumphosphate, dipotassium phosphate, di-ammonium phosphate, sodiumcarbonate, potassium carbonate, ammonium carbonate, sodium hydrogencarbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate,sodium borate, potassium borate and ammonium borate. Specific examplesof such bases also usable herein include organic alkaline agents such asmonomethylamine, dimethylamine, trimethylamine, monoethylamine,diethylamine, triethylamine, mono-isopropylamine, diisopropylamine,triisopropylamine, n-butylamine, monoethanolamine, diethanolamine,triethanolamine, mono-isopropanolamine, diisopropanolamine,ethyleneimine, ethylenediamine and pyridine.

These alkaline agents may be used alone or in any combination of atleast two thereof. Among these alkaline agents, preferred are sodiumhydroxide and potassium hydroxide. This is because the pH value of theresulting developer can be controlled over a wide pH range by adjustingthe amount of the alkaline agent relative to that of the non-reducingsaccharide. Moreover, the alkaline agents also preferably used hereininclude, for instance, trisodium phosphate, tripotassium phosphate,sodium carbonate and potassium carbonate since these agents as such havebuffering effects. These alkaline agents are incorporated into thedeveloper so that the pH value of the developer falls within the rangeof from 9.0 to 13.5 and the amount thereof is thus determined dependingon the desired pH value and the kinds and added amounts of thenon-reducing saccharides selected, but the developer more preferably hasa pH value ranging from 10.0 to 13.2.

Moreover, the developer may likewise simultaneously comprise an alkalinebuffer solution containing a weak acid other than saccharides and astrong base. The weak acid used in such a buffer solution is preferablyone having a dissociation constant (pKa) ranging from 10.0 to 13.2. Suchan acid is selected from those described in “Ionization Constants ofOrganic Acids in Aqueous Solution”, published by Pergamon PressPublishing Company and specific examples thereof are alcohols such as2,2,3,3-tetrafluoropropanol-1 (pKa 12.74), trifluoro-ethanol (pKa 12.37)and trichloro-ethanol (pKa 12.24); aldehydes such as pyridine-2-aldehyde(pKa 12.68) and pyridine-4-aldehyde (pKa 12.05); phenolic hydroxylgroup-containing compounds such as salicylic acid (pKa 13.0),3-hydroxy-naphthoic acid (pKa 12.84), catechol (pKa 12.6), gallic acid(pKa 12.4), sulfo-salicylic acid (pKa 11.7), 3,4-dihydroxy-sulfonic acid(pKa 12.2), 3,4-dihydroxy-benzoic acid (pKa 11.94),1,2,4-trihydroxy-benzene (pKa 11.82), hydroquinone (pKa 11.56),pyrogallol (pKa 11.34), o-cresol (pKa 10.33), resorcinol (pKa 11.27),p-cresol (pKa 10.27) and m-cresol (pKa 10.09); oximes such as2-butanone-oxime (pKa 12.45), acetoxime (pKa 12.42),1,2-cycloheptanedione-dioxime (pKa 12.3), 2-hydroxybenzaldehyde-oxime(pKa 12.10), dimethyl-glyoxime (pKa 11.9), ethane-diamide-dioxime (pKa11.37) and acetophenone-oxime (pKa 11.35); nucleic acid-relatedsubstances such as adenosine (pKa 12.56), inosine (pKa 12.5), guanine(pKa 12.3), cytosine (pKa 12.2), hypoxanthine (pKa 12.1) and xanthine(pKa 11.9); and other weak acids such as diethylamino-methyl phosphonicacid (pKa 12.32), 1-amino-3,3,3-trifluorobenzoic acid (pKa 12.29),isopropylidene diphosphonic acid (pKa 12.10),1,1-ethylidene-diphosphonic acid (pKa 11.54),1,1-ethylidene-diphosphonic acid 1-hydroxy (pKa 11.52), benzimidazole(pKa 12.86), thiobenzamide (pKa 12.8), picoline-thioamide (pKa 12.55)and barbituric acid (pKa 12.5).

Among these weak acids, preferred are sulfo-salicylic acid and salicylicacid. The bases preferably used in combination with these weak acids aresodium hydroxide, ammonium hydroxide, potassium hydroxide and lithiumhydroxide. These alkaline agents may be used alone or in combination ofat least two thereof. The foregoing various kinds of alkaline agents areused such that the pH value of the developer falls within a desiredrange, by properly adjusting the concentration and combination of theagents.

The developer may, if necessary, comprise a variety of surfactantsand/or organic solvent for the promotion of the development, dispersionof development scum and the improvement of the affinity of the imagearea of the printing plate with ink. Preferred surfactants are, forinstance, anionic, cationic, nonionic and amphoteric ones.

Examples of preferred surfactants are nonionic surfactants such aspolyoxy-ethylene alkyl ethers, polyoxyethylene alkylphenyl ethers,polyoxyethylene polystyryl-phenyl ethers, polyoxyethylenepolyoxypropylene alkyl ethers, partial esters of glycerin fatty acids,partial esters of sorbitan fatty acids, partial esters ofpentaerythritol fatty acids, propylene glycol mono-fatty acid esters,partial esters of sucrose fatty acids, partial esters of polyoxyethylenesorbitan fatty acids, partial esters of polyoxyethylene sorbitol fattyacids, polyethylene glycol fatty acid esters, partial esters ofpolyglycerin fatty acids, polyoxyethylene-modified castor oils, partialesters of polyoxyethylene glycerin fatty acids, fatty aciddiethanol-amides, N,N-bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters and trialkylamine oxides;fatty acid salts, abietic acid salts, hydroxyalkane-sulfonic acid salts,alkane-sulfonic acid salts, dialkylsulfo-succinic acid ester salts,linear alkylbenzene-sulfonic acid salts, branched alkylbenzene-sulfonicacid salts, alkylnaphthalene-sulfonic acid salts, alkylphenoxypolyoxyethylene propyl-sulfonic acid salts, polyoxyethylenealkylsulfo-phenyl ether salts, sodium salt of N-methyl-N-oleyltaurine,disodium salts of N-alkylsulfo-succinic acid monoamides, petroleumsulfonic acid salts, sulfated tallow oil, sulfuric acid ester salts offatty acid alkyl esters, alkylsulfuric acid ester salts, polyoxyethylenealkyl ether sulfuric acid ester salts, fatty acid monoglyceride sulfuricacid ester salts, polyoxyethylene alkylphenyl ether sulfuric acid estersalts, polyoxyethylene styrylphenyl ether sulfuric acid ester salts,alkylphosphoric acid ester salts, polyoxyethylene alkyl ether phosphoricacid ester salts, polyoxyethylene alkyl-phenyl ether phosphoric acidester salts, partially saponified products of styrene-maleic anhydridecopolymers and partially saponified products of olefin-maleic anhydridecopolymers; anionic surfactants such as naphthalene sulfonic acidsalts-formalin condensates; cationic surfactants such as alkylaminesalts, quaternary ammonium salts (for instance, tetrabutylammoniumbromide), polyoxyethylene alkylamine salts and polyethylene polyaminederivatives; and amphoteric surfactants such as carboxy betaines,aminocarboxylic acids, sulfo-betaines, amino-sulfuric acid esters andimidazolines. The term “polyoxyethylene” appearing in the nomenclatureof the foregoing surfactants may be replaced with “polyoxyalkylene” suchas “polyoxy-methylene”, “polyoxypropylene” and “polyoxybutylene” andsuch surfactants may likewise be included in the present invention.

More preferred surfactants usable herein include, for instance, fluorineatom-containing surfactants containing perfluoroalkyl groups in themolecule. Examples of such fluorine atom-containing surfactants areanionic type ones such as perfluoroalkyl carboxylic acid salts,perfluoroalkyl sulfonic acid salts and perfluoroalkyl phosphoric acidsalts; amphoteric type ones such as perfluoroalkyl betaines; cationictype ones such as perfluoroalkyl trimethyl ammonium salts; and nonionictype ones such as perfluoroalkylamine oxides, perfluoroalkyl-ethyleneoxide adducts, oligomers containing perfluoroalkyl groups andhydrophilic groups, oligomers containing perfluoroalkyl groups andlipophilic groups, oligomers containing perfluoroalkyl groups,hydrophilic groups and lipophilic groups and urethanes containingperfluoroalkyl groups and lipophilic groups. The foregoing surfactantsmay be used alone or in any combination of at least two of them. Thesesurfactants are added to the developer in an amount ranging from 0.001to 10% by weight and more preferably 0.01 to 5% by weight on the basisof the total amount of the developer.

The developer used in the invention may comprise a variety ofdevelopment stabilizers. Examples of such stabilizers preferably usedherein are polyethylene glycol adducts of sugar alcohols as disclosed inJ.P. KOKAI No. Hei 6-282079, tetraalkyl ammonium salts such astetrabutyl ammonium hydroxide, phosphonium salts such astetrabutyl-phosphonium bromide and iodonium salts such asdiphenyl-iodonium chloride. Preferred examples thereof further includeanionic or amphoteric surfactants disclosed in J.P. KOKAI No. Sho50-51324, water-soluble cationic polymers disclosed in J.P. KOKAI No.Sho 55-95946 and water-soluble amphoteric polyelectrolytes disclosed inJ.P. KOKAI No. Sho 56-142528.

Examples of such stabilizers for the developer further include organicboron atom-containing compounds to which alkylene glycols are added asdisclosed in J.P. KOKAI No. Sho 59-84241,polyoxyethylene-polyoxypropylene block polymer-type water-solublesurfactants disclosed in J.P. KOKAI No. Sho 60-111246, alkylene-diaminecompounds substituted with polyoxyethylene-polyoxypropylene disclosed inJ.P. KOKAI No. Sho 60-129750, polyethylene glycols having a weightaverage molecular weight of not less than 300 disclosed in J.P. KOKAINo. Sho 61-215554, cationic group-containing fluorine atom-containingsurfactants disclosed in J.P. KOKAI No. Sho 63-175858, water-solubleethylene oxide-added compounds obtained by adding not less than 4 molesof ethylene oxide to acids or alcohols as disclosed in J.P. KOKAI No.Hei 2-39157 and water-soluble polyalkylenes compounds.

The developer used herein further comprises, if necessary, an organicsolvent. Such an organic solvent is suitably selected from those havinga solubility in water of not more than about 10% by weight andpreferably not more than 5% by weight. Specific examples thereof include1-phenyl ethanol, 2-phenyl ethanol, 3-phenyl-1-propanol,4-phenyl-1-butanol, 4-phenyl-2-butanol, 2-phenyl-1-butanol, 2-phenoxyethanol, 2-benzyloxy ethanol, o-methoxybenzyl alcohol, m-methoxybenzylalcohol, p-methoxy-benzyl alcohol, benzyl alcohol, cyclohexanol,2-methyl cyclohexanol, 3-methyl cyclohexanol, 4-methyl cyclohexanol,N-phenyl ethanolamine and N-phenyl diethanol-amine.

The content of the organic solvent to be used ranges from 0.1 to 5% byweight on the basis of the total weight of the developer. The amountthereof to be used is closely related to the amount of the surfactantused and the amount of the surfactant to be used is preferably increasedas that of the organic solvent increases. This is because if the amountof the surfactant is small and a large amount of the organic solvent isused, the organic solvent is not completely dissolved and this would inturn make it difficult to ensure good developing ability of theresulting developer.

The developer may further comprise a reducing agent. Such a reducingagent may serve to inhibit any contamination of a printing plate duringdevelopment and the use thereof is effective, in particular, in thedevelopment of a negative light-sensitive lithographic printing platecontaining a light-sensitive diazonium salt compound. Examples oforganic reducing agent preferably used herein include phenol compoundssuch as thiosalicylic acid, hydroquinone, Metol, methoxy-quinone,resorcin and 2-methyl-resorcin and amine compounds such asphenylene-diamine and phenyl hydrazine. In addition, examples ofinorganic reducing agents preferably used herein are salts such assodium, potassium and ammonium salts of inorganic acids such assulfurous acid, hydrogen-sulfurous acid, phosphorous acid,hydrogen-phosphorous acid, dihydrogen-phosphorous acid, thiosulfuricacid and dithionic acid. Among these reducing agents, sulfites areparticularly excellent in the contamination-inhibitory effect. Thedeveloper comprises these reducing agents preferably in an amountranging from 0.05 to 5% by weight on the basis of the weight of thedeveloper practically used.

The developer may further comprise an organic carboxylic acid. Organiccarboxylic acids preferably used herein are aliphatic and aromaticcarboxylic acids having 6 to 20 carbon atoms. Specific examples ofaliphatic carboxylic acids are caproic acid, enanthylic acid, capricacid, lauric acid, myristic acid, palmitic acid and stearic acid, withalkanoic acids having 8 to 12 carbon atoms being particularly preferred.Moreover, aliphatic carboxylic acids may likewise be unsaturated fattyacids containing double bonds in the carbon chains or those havingbranched carbon chains. The aromatic carboxylic acids are compoundshaving benzene, naphthalene and anthracene rings, which are substitutedwith carboxyl groups and specific examples thereof are o-chlorobenzoicacid, p-chlorobenzoic acid, o-hydroxy-benzoic acid, p-hydroxy-benzoicacid, o-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxy-benzoicacid, 2,5-dihydroxy-benzoic acid, 2,6-dihydroxy-benzoic acid,2,3-dihydroxy-benzoic acid, 3,5-dihydroxy-benzoic acid, gallic acid,1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid,2-hydroxy-1-naphthoic acid, 1-naphthoic acid and 2-naphthoic acid, withhydroxy naphthoic acids being particularly effective.

The foregoing aliphatic and aromatic carboxylic acids are preferablyused in the form of sodium, potassium or ammonium salts for the purposeof increasing the water-solubility thereof. In the developer used in theinvention, the content of the organic carboxylic acid is notparticularly restricted, but if the content thereof is less than 0.1% byweight, the effect thereof is insufficient, while if it is not less than10% by weight, not only any further improvement of the effect is notexpected, but also when simultaneously using other additives, thepresence thereof would sometimes interfere with the dissolution of theadditives. For this reason, the added amount of the carboxylic acidpreferably ranges from 0.1 to 10% by weight and more preferably 0.5 to4% by weight on the basis of the total amount of the developerpractically used.

Further, the developer may comprise, if necessary, other additives suchas a preservative, a coloring agent, a thickening agent, an antifoamingagent and a water softener. Examples of water softeners arepolyphosphoric acid and sodium, potassium and ammonium salts thereof;aminopolycarboxylic acids and sodium, potassium and ammonium saltsthereof such as ethylenediaminetetraacetic acid,diethylenetriamine-pentaacetic acid, triethylenetetraminehexaaceticacid, hydroxyethyl ethylenediamine-triacetic acid, nitrilotriaceticacid, 1,2-diaminocyclohexanetetraacetic acid and1,3-diamino-2-propanoltetraacetic acid; andaminotri(methylene-phosphonic acid),ethylenediaminetetra(methylene-phosphonic acid),diethylenetriaminepenta-(methylene-phosphonic acid),triethylenetetraminehexa(methylene-phosphonic acid), hydroxyethylethylenediaminetri(methylene-phosphonic acid) and1-hydroxyethane-1,1-diphosphonic acid and sodium, potassium and ammoniumsalts thereof.

The optimum amount of the water softener may vary depending on thechelating ability thereof, the hardness and amount of water used, butthe amount thereof used in general ranges from 0.01 to 5% by weight andmore preferably 0.01 to 0.5% by weight on the basis of the amount of thedeveloper practically used. If the amount of the softener is less thanthe lower limit, the intended purpose cannot sufficiently beaccomplished, while if it exceeds the upper limit, image areas areadversely affected, for instance, there would be observed colorblinding. The balance of the developer is water. The developer is storedin the form of a concentrate whose water content is lower than that ofthe developer practically used and is diluted with water immediatelybefore the practical use. This concentrate is quite convenient from theviewpoint of transportation thereof. In this case, the developer issuitably concentrated to such an extent or such a degree ofconcentration that all of the components of the developer never undergoany separation or precipitation.

Alternatively, the developer disclosed in J.P. KOKAI No. Hei 6-282079may be used as that used for the development of a lithographic printingplate containing the light-sensitive resin composition according to thepresent invention. This developer is one containing an alkali metalsilicate having a molar ratio: SiO₂/M₂O (wherein M represents an alkalimetal) ranging from 0.5 to 2.0 and a water-soluble ethylene oxide-addedcompound prepared by adding not less than 5 moles of ethylene oxide to asugar alcohol carrying at least 4 hydroxyl groups. In this respect, thesugar alcohol is a polyhydric alcohol corresponding to that obtained byreducing the aldehyde and ketone groups of sugar into primary andsecondary alcohol groups, respectively. Specific examples of such sugaralcohols are D,L-threitol, erythritol, D,L-arabitol, ribitol, xylitol,D,L-sorbitol, D,L-mannitol, D,L-iditol, D,L-talitol, dulcitol andallo-dulcitol as well as di-, tri-, tetra-, penta- and hexa-glycerinobtained by condensing sugar alcohols. The foregoing water-solubleethylene oxide adducts each can be prepared by adding not less than 5moles of ethylene oxide to one mole of the foregoing sugar alcohol.Moreover, the ethylene oxide adducts may, if necessary, be furtherblock-copolymerized with propylene oxide to such an extent that adesired solubility of the product can be ensured. These ethylene oxideadducts may be used alone or in any combination of at least two of them.The amount of these water-soluble ethylene oxide-adducts to be addedsuitably ranges from 0.001 to 5% by weight and more preferably 0.001 to2% by weight on the basis of the amount of the developer (practicallyused).

The developer may, if necessary, comprise various kinds of surfactantsand/or organic solvent such as those listed above for the promotion ofthe development, dispersion of development scum and the improvement ofthe affinity of the image area of the printing plate with ink.

The PS plate treated with a developer having such a composition issubjected to post-treatments using a rinsing liquid containing, forinstance, washing water and a surfactant, a finisher comprising gumarabic and a starch derivative as principal components and/or aprotective gumming solution. In the post-treatments of the PS plateaccording to the present invention, it is possible to use variouscombinations of these treatments.

Recently, there has widely been used an automatic developing machine forPS plates for the rationalization and standardization of theplate-making operations in the fields of patterned plates and printing.This automatic developing machine in general comprises a developingportion and a post-treatment portion and includes a device fortransporting the PS plates, baths or tanks for accommodating processingliquids and a spraying device. In this automatic machine, imagewiseexposed PS plates are horizontally conveyed while each processing liquidpumped up is sprayed on the PS plates through a spray nozzle to thusconduct development and post-treatments. Recently, there has also beenknown a method in which a PS plate is transported and immersed inprocessing baths each filled with a corresponding processing liquid bymeans of dipped guide rolls to thus develop and post-treat the PS plateor a method in which a small constant amount of washing water is fed tothe plate surface after the development to thus wash the same with waterand the resulting waste water is reused as a diluting water for thestock solution of the developer.

In such an automatic processing, the PS plate may be processed while areplenisher for each processing liquid is supplemented to the liquiddepending on, for instance, the throughput and the running time of themachine. Alternatively, the so-called disposition method may be used, inwhich a PS plate is processed with a substantially fresh processingliquid. The lithographic printing plate prepared after such treatmentsis fitted to an offset printing press to obtain a plurality of printedmatters.

The present invention will hereunder be described in more detail withreference to the following working Examples, but the present inventionis not restricted to these specific Examples at all. In the followingExamples, the term “%” means “% by weight” unless otherwise specified.

EXAMPLES 1 TO 10 AND COMPARATIVE EXAMPLES 1 AND 2

A JIS A 1050 aluminum plate having a thickness of 0.24 mm was subjectedto a brush-graining treatment in which the plate was rubbed with thefollowing rotating nylon brushes while supplying an aqueous suspensionof pumice stone having an average particle size of about 2.1 μm. A firstbrush had a bristle length of 100 mm, a bristle diameter of 0.95 mm anda plantation density of 70 bristles/cm² and a second brush had a bristlelength of 80 mm, a bristle diameter of 0.295 mm and a plantation densityof 670 bristles/cm². Both of the rotational frequencies of these twobrush rolls were set at 250 rpm. After sufficiently washing the aluminumplate with water subsequent to the brush graining, the plate was etchedby immersing it in a 10% sodium hydroxide solution at 60° C. for 25seconds, followed by washing with running water, rinse andneutralization of the same with a 20% nitric acid solution and thenwashing with water. The aluminum plate was then subjected to anelectrolytic surface-roughening treatment in a 1% nitric acid aqueoussolution, at the quantity of electricity at the anode time of 160coulomb/dm², using a sinusoidal alternating waved current under thecondition of VA=12.7 V. At this stage, the surface roughness of theresulting aluminum plate was determined to be 0.79 μm (as expressed interms of Ra). Subsequently, the plate was immersed in a 1% sodiumhydroxide aqueous solution at 40° C. for 30 seconds, further immersed ina 30% sulfuric acid aqueous solution to carry out the desmutting thereofat 60° C. for 40 seconds and then anodized at a current density of2A/dm², using a DC current so that the weight of the resulting anodizedfilm was equal to 1.6 g/m² to thus prepare a substrate.

An undercoating liquid 1 having the following composition was appliedonto the surface of the substrate thus treated and dried at 80° C. for30 seconds. The amount of the coated film weighed after drying was foundto be 10 mg/m².

(Undercoating Liquid 1) β-Alanine 0.10 g Methanol   40 g Pure Water   60g

Thus, a substrate (I) was prepared. Then 12 ml/m² of a light-sensitiveliquid 1 (composition) detailed below was applied onto the substrate (I)according to the rod coating and then dried at 100° C. for one minute togive a positive light sensitive presensitized plate for preparing alithographic printing plate. The amount of the coated liquid weighedafter drying was found to be 1.15 g/m². Moreover, a matting layer wasformed according to the disclosure of J.P. KOKOKU No. Sho 61-28986 inorder to reduce the time required for the adhesion under vacuum.

(Composition of Light-Sensitive Liquid 1) Amt. Component (g) Esterifiedproduct of 1,2-diazonaphthoquinone-5-sulfonylchloride 0.8 andpyrogallol-acetone resin (the substance disclosed in Example 1 of U.S.Pat. No. 3,635,709) Cresol-formaldehyde novolak resin (m/p ratio 6:4;weight 1.5 average molecular weight 8000) Phenol-formaldehyde resin(weight average molecular 0.3 weight 15,000)Poly[N-(p-aminosulfonylphenyl)acrylamide-co-n-butyl 0.2acrylate-co-diethylene glycol monomethyl ether methacrylate] (molarratio of monomers (in this order) 40:40:20; weight average molecularweight 40,000; number average molecular weight 20,000)p-n-Octylphenol-formaldehyde resin (the substance 0.02 disclosed in U.S.Pat. No. 4,123,279) Naphthoquinonediazide-1,2-diazide-4-sulfonic acidchloride 0.01 Tetrahydrophthalic acid anhydride 0.02 Pyrogallol 0.054-[p-N,N-Bis(ethoxycarbonyl-methyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine 0.07 A dye obtained by substituting1-naphthalene-sulfonic acid 0.045 for the counter-anion of Victoria PureBlue BOH (available from Hodogaya Chemical Co., Ltd.) Fluorineatom-containing polymer (see Table 2) See Table 2MEK/1-methoxy-2-propanol 15/10

TABLE 2 Amt. Added Fluorine-containing (solid polymer content) (g)Light-Sensitive Material 1 (Ex.) P-1 0.015 Light-Sensitive Material 2(Ex.) P-4 0.02 Light-Sensitive Material 3 (Ex.) P-7 0.02 Light-SensitiveMaterial 4 (Ex.) P-9 0.01 Light-Sensitive Material 5 (Ex.) P-10 0.03Light-Sensitive Material 6 (Ex.) P-14 0.015 Light-Sensitive Material 7(Ex.) P-18 0.025 Light-Sensitive Material 8 (Ex.) P-24 0.02Light-Sensitive Material 9 (Ex.) P-16 0.01 Light-Sensitive Material 10(Ex.) P-29 0.02 Light-Sensitive Material R1 R-1 (having the 0.015 (Comp.Ex.) following structure) Light-Sensitive Material R2 R-2* (having the0.025 (Comp. Ex.) following structure) Light-Sensitive Material R3 Notadded None (Comp. Ex.) *The compound disclosed in Example 1 of J. P.KOKAI No. Sho 62-170950.

In addition, the surface condition of the coated light-sensitive layeron the light-sensitive printing plate thus prepared was observed withthe naked eyes. The surface condition was evaluated on the basis of thenumber of pinholes formed per unit area of the surface (1 m²).

The presensitized plate for light-sensitive lithographic printing platesthus prepared was evaluated according to the following method. Thepresensitized plate was exposed to light from a 3 kW metal halide lampat a distance of 1.5 m from the plate for one minute through a solidmanuscript or a manuscript carrying half tone dots, the followingdeveloper and FP2W (1:1) (available from Fuji Photo Film Co., Ltd.) as afinisher were introduced into PC Processor 900V (available from FujiPhoto Film Co., Ltd.), the plate was developed in this apparatus at 30°C. for 12 seconds to give a lithographic printing plate. Then printingoperations were carried out using R201 Printing Press (available fromRoland Company) and GEOS-G (N) (available from Dainippon Ink andChemicals, Inc.) as ink to examine the number of printed mattersrequired till the image area at the initiation of the printing had asufficient ink density and to thus determine the number of printedmatters required till the plate sufficiently received ink. In thisrespect, the smaller the numerical value, the better the resultinglithographic printing plate. Moreover, the printing operation wascontinued till the printed matter caused blurring on the solid portionthereof to determine the number of printed matters obtained before thesolid portion underwent blurring and to evaluate the printing durabilityof the lithographic printing plate. In this connection, the larger thenumber of acceptable printed matters, the higher the printing durabilityof the lithographic printing plate. The results thus obtained aresummarized in the following Table 3.

(Composition of Developer) Component Amt. (% by weight) Pure water 90D-Sorbitol 6 KOH 2.5

TABLE 3 Light- No. of Ex. Sensitive Printed Printing No. MaterialSurface Condition Matters¹⁾ Durability  1 1 Not more than 5 15 150,000 2 2 Not more than 5 13 160,000  3 3 Not more than 5 16 180,000  4 4 Notmore than 5 11 180,000  5 5 Not more than 5 14 160,000  6 6 Not morethan 5 12 170,000  7 7 Not more than 5 15 150,000  8 8 5 to 10 13160,000  9 9 Not more than 5 16 170,000 10 10 Not more than 5 12 150,000 1* R1 Not less than 10 30 120,000  2* R2 Not less than 10 25 110,000 3* R3 Entirely speckled and non-uniform film *Comparative Example ¹⁾Thenumber of printed matters required till the printing plate completelyreceives ink.

As will be clear from the data listed in Table 3, the light-sensitivelayer of the presensitized plate for lithographic printing platesaccording to the present invention, which makes use of specific fluorineatom-containing polymers is excellent in the uniformity. Moreover, thepresensitized plate can provide a lithographic printing plate excellentin both the ink-receptivity and the printing durability. Morespecifically, it could be recognized that the use of a fluorineatom-containing polymer obtained by selecting a fluorine-containingmonomer and a copolymerizable monomer having a specific structurepermits the improvement of the coated surface condition of the originallithographic printing plate and the improvement of the ink-receptivityand printing durability of the resulting lithographic printing plate.

EXAMPLES 11 TO 15 AND COMPARATIVE EXAMPLE 4

The same procedures used for the preparation of the light-sensitivematerial 1 were repeated except that the fluorine atom-containingpolymers listed in the following Table 4 were substituted for thefluorine atom-containing polymer used for preparing the material 1 togive presensitized plates for lithographic printing plates orlight-sensitive materials 10 to 15 and R4.

TABLE 4 Light-Sensitive Fluorine Atom-Containing Amt. Added (Conc. ofMaterial No. Polymer solid Content (g)) 11 (Ex.) P-3 0.015 12 (Ex.) P-60.02 13 (Ex.) P-9 0.05 14 (Ex.) P-15 0.06 15 (Ex.) P-23 0.1 R4 (Comp.Ex.) R-3 (having the 0.1 following structure)

The presensitized plates for light-sensitive lithographic printingplates thus prepared were evaluated according to the following methods.The sensitivity thereof was evaluated by means of the number of clearsteps, which was determined by exposing them to the light rays from a 3kW metal halide lamp positioned at a distance of 1 m from thepresensitized plate for one minute through a step wedge (densitydifference between every neighboring two steps was set at 0.15)(available from Fuji Photo Film Co., Ltd.) and developing each exposedplate with an aqueous solution having a molar ratio: SiO₂/K₂O of 1.16and an SiO₂ concentration of 1.4% as a developer in PS Processor 900V(available from Fuji Photo Film Co., Ltd.) to thus determine the numberof clear steps for each plate. In this respect, the higher the number ofclear steps, the higher the sensitivity of the correspondingpresensitized plate. The gradation was herein defined to be thedifference between the number of clear steps of each sample determinedby the foregoing method and the number of solid steps thereof. Regardingthe gradation, the lower the difference, the higher the contrast of thecorresponding sample. The development latitude of each sample wasexpressed in terms of the pH-dependent change in the number of solidsteps, which was determined by repeating the same procedures forexposure to light and development used for the determination of thesensitivity except that the pH value of the developer was increased anddecreased by 0.2 relative to that of the foregoing developer as astandard to thus determine the intended change. In this respect, thesmaller the resulting value or change, the better the developmentlatitude of each sample. The results thus obtained are summarized in thefollowing Table 5.

TABLE 5 Light-Sensitive Development Ex. No. Material No. SensitivityGradation Latitude 11 11 6.0 5.5 6 12 12 6.25 5.0 5 13 13 6.25 5.0 5 1414 6.0 5.25 6 15 15 6.0 5.5 5  4* R4 5.75 6.0 7 *Comparative Example

As will be clear from the data listed in Table 5, the contrast of eachproduct of Examples 11 to 15 is increased without any reduction of thesensitivity and the development latitude thereof is also excellent.

EXAMPLES 16 TO 20 AND COMPARATIVE EXAMPLES 5 TO 7

A band-like aluminum plate having a thickness of 0.3 mm and a width of1,000 mm was first passed through a 10% sodium tertiary phosphateaqueous solution maintained at 80° C. for one minute to carry outdegreasing of the aluminum plate. Then the surface of the aluminum platewas grained using a nylon brush and an aqueous suspension of pumicestone (400 mesh) and sufficiently washed with water. Subsequently, theplate was etched by immersing it in a 25% sodium hydroxide aqueoussolution maintained at 45° C. for 9 seconds, followed by washing withwater, immersion thereof in a 20% nitric acid solution for 20 secondsand washing with water. At this stage, the amount of aluminum removedfrom the grained aluminum plate through the etching was found to beabout 8 g/m². Then this plate was anodized in a 7% sulfuric acidsolution as an electrolyte at a DC current density of 15 A/dm² to forman anodized film in an amount of 3 g/m², followed by washing the platewith water, drying the same and application of the followinglight-sensitive liquid 2 onto the surface of the aluminum plate thustreated.

(Composition of Light-Sensitive Liquid 2) Amt. Component (g) Esterifiedproduct of naphthoquinone-1,2-diazide-5- 0.90 sulfonylchloride andpyrogallol-acetone resin (the substance disclosed in Example 1 of U.S.Pat. No. 3,635,709) Cresol-formaldehyde resin (the substance disclosedin U.S. 2.00 Pat. No. 4,123,279) t-Butylphenol-formaldehyde resin (thesubstance disclosed 0.05 in U.S. Pat. No. 4,123,279)Naphthoquinone-1,2-diazide-5-sulfonylchloride 0.03 Oil Blue #603(available from ORIENT Chemical Industries 0.05 Inc.) Fluorineatom-containing polymer (see Table 6) 0.015 Methyl ethyl ketone 8Propylene glycol monomethyl ether 25

The foregoing coating liquid was continuously applied onto the surfaceof the grained band-like aluminum plate at a rate of 30 g/m², followedby drying the same by passing it through a hot air-drying zonemaintained at 100° C. for one minute to thus form a light-sensitivelayer.

TABLE 6 Fluorine Uniformity of No. Of Printing Ex. Atom-ContainingLight-Sensitive Printed Durability No. Polymer Layer¹⁾ Matters²⁾ (No. OfSheet) 16 P-2 A 25 150,000 17 P-6 A 24 160,000 18 P-9 A 25 150,000 19P-15 A 26 170,000 20 P-24 A 24 160,000  5* R-1 B 30 120,000  6* R-2 A 36130,000  7* Not added D 25 100,000 *Comparative Example ¹⁾This wasevaluated on the basis of the following criteria: A: Uniform and even;B: Slightly and lightly uneven; C: There was observed unevenness due to,for instance, the drying air-blow; and D: There was observedconsiderable unevenness due to, for instance, the drying air-blow. ²⁾Thenumber of printed matters required till the printing plate completelyreceives ink.

As will be seen from the data listed in Table 6, the light-sensitivelayers prepared in Examples 16 to 20 using the fluorine atom-containingsurfactant according to the present invention have a quite uniform filmthickness as compared with that observed for the light-sensitive layerprepared in Comparative Example 7 without using any such surfactant.Moreover, the light-sensitive layers prepared in Comparative Examples 5and 6 using fluorine atom-containing polymers beyond the scope of thepresent invention are found to be insufficient in the uniformity of thecoated films. Furthermore, each presensitized plate thus prepared wasexposed to light through an image-carrying film and developed at 25° C.for 40 seconds using an automatic developing machine 800U (availablefrom Fuji Photo Film Co., Ltd.) and an automatic developer DP-4 (1:8)(available from the same company). Then a gum (GP) (available from thesame company) was applied to the developed plate and printing wascarried out using the plate thus formed after one week to thus determinethe ink-receptivity in terms of the number of printed matters obtainedtill the ink was completely adhered to the plate surface. As a result,it was found that the products of Comparative Examples 5 and 6 wereinferior in the ink-receptivity.

Each of the light-sensitive lithographic printing plates prepared inExamples 16 to 20 was subjected to contact exposure with an originalfilm and then developed with a developer for positive plates. As aresult, it was found that these lithographic printing plates wereexcellent in both the sensitivity and the ability of reproducing theoriginal pattern. Printing was conducted using these lithographicprinting plates and it was found that they were excellent in both theprinting durability and the uniformity of image strength.

EXAMPLE 21 AND COMPARATIVE EXAMPLES 8 AND 9

The surface of an aluminum plate of quality 1S having a thickness of0.30 mm was grained with a number 8 nylon brush and an aqueoussuspension of 800 mesh pumice stone and then the plate was sufficientlywashed with water. The plate was then etched by immersing in a 10%sodium hydroxide solution at 70° C. for 60 seconds, washed with runningwater, neutralized and rinsed with a 20% HNO₃ solution and then washedwith water. The plate was then subjected to an electrolyticsurface-roughening treatment in a 1% nitric acid aqueous solution at thequantity of anode time electricity of 300 coulomb/dm² using a sinusoidalalternating waved current under the condition of VA=12.7 V. At thisstage, the surface-roughness thereof was determined and it was found tobe 0.45 μm (as expressed in terms of Ra). Subsequently, the plate wasdesmutted by immersing it in a 30% sulfuric acid aqueous solution at 55°C. for 2 minutes, a cathode was placed on the grained surface of theplate in a 20% sulfuric acid aqueous solution at 33° C. and the platewas anodized at a current density of 5 A/dm² for 50 seconds. Thethickness of the anodized film thus formed was determined and found tobe 2.7 g/m².

Further the plate was immersed in a 2.5% by weight aqueous solution ofNo. 3 sodium silicate (SiO₂=28˜30%; Na₂O=9˜10%; Fe=not more than 0.02%)having a pH value of 11.2 and maintained at 70° C. for 13 seconds andthen washed with water. At this stage, the amount of silicate depositedwas found to be 10 mg/m². This was determined by the fluorescent X-rayanalysis in terms of the amount of elemental Si. Then a liquidcomposition (sol) for the SG method was prepared according to thefollowing procedures. The following composition was weighed out in abeaker and stirred at 25° C. for 20 minutes.

(Composition of Sol) Component Amt. (g) Si(OC₂H₅)₄ 383-Methacryloxypropyl trimethoxysilane 13 85% phosphoric acid aqueoussolution 12 Ion-exchanged water 15 Methanol 100

The solution was transferred to a 3-necked flask, a reflux condenser wasfitted to the flask and the flask was then immersed in an oil bathmaintained at room temperature. The temperature of the contents in theflask was raised up to 50° C. over 30 minutes, while stirring them usinga magnetic stirrer. The contents were further reacted for one hour whilemaintaining the bath temperature at 50° C. to thus give a liquidcomposition (sol). The resulting sol was diluted with 20/1 (weightratio) mixture of methanol and ethylene glycol to a final concentrationof 0.5% by weight, applied onto the substrate according to the whirlercoating technique and then dried at 100° C. for one minute. At thisstage, the coated amount thereof was found to be 4 mg/m². This coatedamount was likewise determined by the fluorescent X-ray analysis andexpressed in terms of the amount of elemental Si. Then a light-sensitiveliquid 3 having the following composition (a photopolymerizablecomposition) was applied onto the aluminum plate thus processed in sucha manner that the coated amount (weighed after drying) was equal to 1.5g/m² and dried at 100° C. for one minute to thus form a light-sensitivelayer.

(Composition of Light-Sensitive Liquid 3) Amt. Component (g)Tetramethylolmethane tetraacrylate 1.5 Linear organic high molecularweight polymer (B1) (allyl 2.0 methacrylate- methacrylic acid copolymer;copolymerization molar ratio 80/20; weight average molecular weight =45,000) Sensitizer (C1; having the following structure) (λ_(max) THF0.15 479 nm; ε = 6.9 × 10⁴) Photopolymerization initiator (D1; havingthe following 0.2 structure) IRUGACURE 907 (E1) (available fromCiba-Geigy Company) 0.4 Fluorine atom-containing polymer (P-9) 0.2 ε-Phthalocyanine/(B1) dispersion 0.2 Methyl ethyl ketone 9.0 Propyleneglycol monomethyl ether acetate 7.5 Toluene 11.0

A 3% by weight aqueous solution of polyvinyl alcohol (degree ofsaponification 98 mole %; degree of polymerization 500) was applied ontothe light-sensitive layer as an oxygen barrier protective layer suchthat the dry weight thereof coated was equal to 2.5 g/m², dried at 120°C. for 3 minutes to give a photopolymerizable presensitized plate forlithographic printing plates. The resulting light-sensitive layer wasexcellent in the uniformity of the coated film (Example 21).

On the other hand, when the fluorine atom-containing polymer (P-9) wasremoved from the light-sensitive layer having the foregoing composition,the resulting film was uneven and non-uniform (Comparative Example 8).

Further a comparative light-sensitive liquid was also prepared accordingto the same procedures used above except that the foregoing R-1 wassubstituted for the P-9 used above. As a result, it was confirmed thatthe foaming ability of the light-sensitive liquid was controlled in caseof the system containing P-9, while the system containing R-1 showedhigh foaming ability and pinholes were formed on the light-sensitivelayer prepared from the R-1 containing system (Comparative Example 9) ina density of not less than 10 per unit area (1 m²).

The resulting lithographic printing plate was exposed to light, in twoparts per plate, using XLP4000 (Ar laser, 75 mW, 488 nm; available fromOptronics Company) under the conditions of the exposure of 4000 dpi and175 lines/inch, every 1% over 1 to 99%. Thereafter, the plate wassubjected to a post-heat treatment by exposing to 120° C. for 20seconds.

The development of the exposed plate was conducted by immersing it inthe following developer at 25° C. for 30 seconds.

(Developer) No. 1K Potassium Silicate  30 g Potassium Hydroxide  15 gWater 1000 g

Then a gumming liquid GU-7 (available from Fuji Photo Film Co., Ltd.)was diluted two times with water and used for the gumming treatment ofthe plate surface. The quantity of energy reproduced on the platesurface by the 1% exposure under the conditions of the exposure of 4000dpi and 175 lines/inch was determined as the sensitivity of each sampleand as a result, it was found to be 0.2 mJ, which corresponded topractically satisfied sensitivity. Moreover, the quality of the halftone dots was excellent at that exposure value and there was notobserved any unnecessary fog and flare at all. Then the test forprinting durability was conducted using SORKZ available from HeidelbergCompany as a printing press and KURAF G (N) available from Dainippon Inkand Chemicals, Inc. as ink and as a result, not less than 180,000excellent printed matters were obtained (Example 21).

Furthermore, the same procedures for the exposure and development usedabove were repeated after the light-sensitive material was stored at 60°C. for 3 days and the stability thereof with time was visuallyevaluated. All of the examined printing durability, resistance tocontamination and image quality were almost identical to those observedfor the light-sensitive material immediately after the coating and quiteexcellent (Example 21).

On the other hand, a light-sensitive presensitized plate forlithographic printing plates having a light-sensitive layer in which R-1was substituted for the P-9 used above was exposed to light anddeveloper by the same procedures used above. As a result, it wasconfirmed that there were observed unnecessary fog and flare(Comparative Example 9).

EXAMPLE 22 AND COMPARATIVE EXAMPLE 10 AND 11

Then we will hereunder explain embodiments concerning the thermallycross-linkable presensitized plate for lithographic printing plates.

An aluminum plate (made of a material 1050) having a thickness of 0.30mm was rinsed with trichloroethylene to thus degrease the same,subjected to surface-graining using a nylon brush and an aqueoussuspension of 400 mesh pumice stone and then sufficiently washed withwater. This plate was etched by immersing in a 25% sodium hydroxideaqueous solution maintained at 45° C. for 9 seconds, washed with water,further immersed in a 2% nitric acid solution for 20 seconds and thenwashed with water. At this stage, the amount of aluminum removed fromthe grained surface through the etching was found to be about 3 g/m².Then an anodized film was formed on this plate at a DC current densityof 15 A/dm² in a 7% sulfuric acid solution as an electrolyte in anamount of 3 g/m² and then washed with water and dried.

Thereafter the following undercoating liquid 2 was applied onto thealuminum plate and dried at 80° C. for 30 seconds. The coated amount ofthe liquid weighed after drying was found to be 10 mg/m².

(Undercoating Liquid 2) β-Alanine  0.1 g Phenyl-phosphonic acid 0.05 gMethanol   40 g Pure water   60 g

Then the following light-sensitive liquid 4 was prepared, the resultingliquid was applied onto the aluminum plate on which the foregoingundercoating layer had been applied and then dried at 100° C. for oneminute to give a negative presensitized plate for lithographic printingplates. The coated surface condition of the light-sensitive layer wasexcellent and uniform and the coated amount thereof weighed after dryingwas found to be 1.5 g/m².

Example 22

(Composition of Light-Sensitive Liquid 4) Component Amt. (g) Fluorineatom-containing polymer (P-9) 0.05 Acid-generating agent [SH-1] (havingthe following 0.3 structure) Crosslinking agent [KZ-1] (having thefollowing 0.5 structure) Binder polymer [BP-1]¹⁾ 1.5 Infrared-absorbingagent [IK-1] (having the following 0.07 structure) AIZEN SPILON BLUEC-RH (available from Hodogaya 0.035 Chemical Co., Ltd.) Methyl ethylketone 12 Methyl alcohol 10 1-Methoxy-2-propanol 8 ¹⁾Binder polymer[BP-1]: A poly(p-hydroxystyrene) product commercially available fromMaruzen Petrochemical Co., Ltd. under the trade name of “Maruka LinkerS-4P” was used as [BP-1].

The surface of the resulting negative presensitized plate for preparinglithographic printing plates was touched with bare hands and then it wasscanning-exposed to the light beam from a semiconductor laser capable ofemitting infrared light rays falling within the wavelength range of from820 to 850 nm. After the exposure, the plate was heated with a panelheater at 110° C. for 30 seconds and then developed with a developerDP-4 (diluted to a ratio of 1:8 with water) (available from Fuji PhotoFilm Co., Ltd.). After the formation of images, the plate was visuallyexamined on whether the images formed on the portions touched with barehands were slipped off or not, but it was confirmed that any image wasnot slipped off at all (Example 22).

Separately, 1 m² of the presensitized plate for lithographic printingplates was treated with 100 ml of the developer and the developer afterthe treatment was inspected for the generation of any sludge. However,there was not observed the generation of any sludge and it was thusconfirmed that the presensitized plate was excellent in the solubilityin the developer (Example 22).

A solution was prepared by repeating the same procedures used in Example22 except that the use of the fluorine atom-containing polymer P-9incorporated into the light-sensitive liquid 4 used in Example 22 wasomitted. This light-sensitive liquid or solution was applied onto theundercoating layer-carrying aluminum plate used in Example 22 and thendried at 100° C. for one minute to form a negative lithographic printingplate material. The conditions of the coated surface were found to beuneven and non-uniform. Images were formed on this presensitized platefor preparing lithographic printing plates by repeating the sameprocedures used in Example 22. After the formation of the images, theplate was visually examined on whether the images formed on the portionstouched with bare hands were slipped off or not and it was confirmedthat images were distinctly slipped off (Comparative Example 10).

Moreover, a light-sensitive liquid was prepared by repeating the sameprocedures used in Example 22 except that R-2 was substituted for thefluorine atom-containing polymer P-9 incorporated into thelight-sensitive liquid 4 of Example 22. This light-sensitive liquid wasapplied onto the undercoating layer-carrying aluminum plate used inExample 22 and then dried at 100° C. for one minute to form a negativelithographic printing plate material. Images were formed on thispresensitized plate for preparing lithographic printing plates byrepeating the same procedures used in Example 22. After the formation ofthe images, the plate was visually examined on whether the images formedon the portions touched with bare hands were slipped off or not and itwas confirmed that images were slipped off (Comparative Example 11).

Separately, 1 m² of the presensitized plate for lithographic printingplates was treated with 100 ml of the developer and the developer afterthe treatment was inspected for the generation of any sludge. As aresult, it was confirmed that sludge was generated and that thepresensitized plate was inferior in the solubility and dispersibility inthe developer.

EXAMPLE 23 AND COMPARATIVE EXAMPLES 13 AND 14

Next, we will hereunder explain embodiments of thermally positivepresensitized plate for preparing lithographic printing plates.

Preparation of Copolymer 1

To a 20 ml volume 3-necked flask equipped with a stirring machine, acondenser and a dropping funnel, there were added 4.61 g (0.0192 M) ofN-(p-aminosulfonyl-phenyl)methacrylamide, 2.94 g (0.0258 M) of ethylmethacrylate, 0.80 g (0.015 M) of acrylonitrile and 20 g ofN,N-dimethylacetamide and the mixture was stirred while heating them ina warm water bath maintained at 65° C. To this mixture, there was added0.15 g of “V-65” (available from WAKO Pure Chemical Co., Ltd.) and theresulting mixture was stirred for 2 hours in a nitrogen gas stream whilemaintaining the temperature of the mixture at 65° C. To this reactionmixture, there was further dropwise added, through the dropping funnel,a mixture containing 4.61 g of N-(p-aminosulfonylphenyl)methacrylamide,2.94 g of ethyl methacrylate, 0.80 g of acrylonitrile,N,N-dimethylacetamide and 0.15 g of “V-65”, over 2 hours.

After the completion of the dropwise addition, the resulting mixture wasfurther stirred at 65° C. for additional 2 hours. After the completionof the reaction, 40 g of methanol was added to the reaction mixture,followed by cooling the mixture, addition of the resulting mixture to 2liters of water with stirring, stirring the resulting mixture over 30minutes, filtration off the precipitates formed in the mixture throughfiltration and then drying the precipitates to give 15 g of a whitesolid. The weight average molecular weight of the resulting specificcopolymer 1 was determined by the gel permeation chromatography(reference material: polystyrene) and as a result, it was found to be53,000.

An aluminum plate (made of a material 1050) having a thickness of 0.30mm was rinsed with trichloroethylene to thus degrease the same,subjected to surface-graining using a nylon brush and an aqueoussuspension of 400 mesh pumice stone and then sufficiently washed withwater. This plate was etched by immersing in a 25% sodium hydroxideaqueous solution maintained at 45° C. for 9 seconds, washed with water,further immersed in a 20% nitric acid solution for 20 seconds and thenwashed with water. At this stage, the amount of aluminum removed fromthe grained surface through the etching was found to be about 3 g/m².Then an anodized film was formed on this plate at a DC current densityof 15 A/dm² in a 7% sulfuric acid solution as an electrolyte in anamount of 3 g/m², washed with water, dried, coated with the followingundercoating liquid 3 and dried at 90° C. for one minute. The coatedamount of the liquid weighed after drying was found to be 10 mg/M².

(Undercoating Liquid 3) β-Alanine 0.5 g Methanol  95 g Water   5 g

Furthermore the plate was treated with a 2.5% by weight aqueous solutionof sodium silicate at 30° C. for 10 seconds, the following undercoatingliquid 4 was applied and the coated layer was dried at 80° C. for 15seconds to give a substrate. The coated amount of the layer weighedafter drying was found to be 15 mg/m².

(Undercoating Liquid 4) The following compound  0.3 g Methanol  100 gWater   1 g

(Molecular weight: 28,000)

The following light-sensitive liquid 5 was prepared. The light-sensitiveliquid 5 was applied onto the resulting substrate in a coated amount of1.8 g/m² to give a presensitized plate for lithographic printing plates,excellent in the conditions of the coated surface of the light-sensitivelayer (Example 23).

(Composition of Light-Sensitive Liquid 5) Component Amt. (g) Fluorineatom-containing polymer (P-12) 0.02 g The foregoing copolymer 1 0.75 gm-,p-Cresol-novolak resin (m/p ratio: 6/4, weight average 0.25 gmolecular weight: 3,500, containing 0.5% by weight of unreacted cresol)p-Toluene-sulfonic acid 0.003 g Tetrahydrophthalic acid anhydride 0.03 gCyanine dye (IK-1) 0.017 g A dye obtained by exchanging the counter-ionsof Victoria 0.015 g Pure Blue BOH for 1-naphthalene-sulfonic acid anionsγ-Butyrolactone 10 g Methyl ethyl ketone 10 g 1-Methoxy-2-propanol 1 g

The resulting presensitized plate for lithographic printing plates wasevaluated for the development stability against any external defectaccording to the following method. Using a continuous load-type scratchresistance-testing machine “SB62 Type” (available from Shinto KagakuCo., Ltd.), paper filter “No. 5C” (available from Advantech Toyo Co.Ltd.) was adhered to a square flat portion (1 cm square) on a scratchingtool, which came in contact with the plate surface and thelight-sensitive layer side of the presensitized plate was scratched at avelocity of 6 cm/sec while adding a load of 100 g to the scratchingtool. Then the scratched presensitized plate was imagewise exposed so asto have 5% half tone dot pattern at a main scanning speed of 5 m/sec,using a semiconductor laser having a power of 500 mW, a beam wavelengthof 830 nm and a beam diameter of 17 μm (1/e²) and the imagewise exposedplate was developed with a developer DP-4 (1:8) (available from FujiPhoto Film Co., Ltd.) for 30 seconds. The resulting plate had anexcellent half tone dot pattern, images formed on the scratched portionwere never dissolved in the developer and it was thus confirmed that thelithographic printing plate according to the present invention showedexcellent development stability against external defects. Moreover, thefoaming ability of the light-sensitive liquid was quite low and thecondition of the coated surface was found to be quite good such that thepinhole density was found to be not more than 5/m² (Example 23).

Separately, 1 m² of the presensitized plate for lithographic printingplates was entirely exposed to light, treated with 100 ml of thedeveloper and the developer after the treatment was inspected for thegeneration of any sludge. As a result, it was confirmed that sludge wasnot generated at all and that the presensitized plate was excellent inthe solubility in the developer.

A presensitized plate for lithographic printing plate was prepared byrepeating the same procedures used in Example 23 except that anyfluorine atom-containing polymer was not used. As a result, the surfacecondition of the resulting light-sensitive layer was found to be unevenand non-uniform. Then this presensitized plate was inspected for thedevelopment stability against external defects according to the sameprocedures used in Example 23. As a result, it was confirmed thatunexposed half tone dot pattern on the scratched portions of the plate,on which images were naturally formed, was removed through thedevelopment (Comparative Example 14).

Separately, 1 m² of the presensitized plate for lithographic printingplates was entirely exposed to light, treated with 100 ml of thedeveloper and the developer after the treatment was inspected for thegeneration of any sludge. As a result, it was confirmed that thegeneration of sludge was distinctly observed and that the presensitizedplate was inferior in the solubility and dispersibility in thedeveloper.

As will be clear from the results observed in Example 23 and ComparativeExamples 13 and 14, the addition of a specific fluorine atom-containingpolymer permits the preparation of a light-sensitive liquid capable ofproviding excellent surface conditions, the resulting light-sensitivelayer is improved in the resistance to external defects prior to thedevelopment, is excellent in the solubility and dispersibility in thedeveloper and does not cause the generation of any sludge.

EXAMPLE 24 AND COMPARATIVE EXAMPLES 15 AND 16

Then we will hereunder explain embodiments of a radical polymerizableand thermally negative presensitized plate for preparing lithographicprinting plates.

A molten metal of JIS A 1050 alloy containing not less than 99.5%aluminum, 0.30% Fe, 0.10% Si, 0.02% Ti and 0.013% Cu was subjected to acleaning treatment and then casted. The cleaning treatment included adegassing treatment for removing unnecessary gases such as hydrogen gasin the melt and a treatment with a ceramic tube filter. The casting wasconducted according to the DC casting method. The solidified ingothaving a thickness of 500 nm was converted into a rolled aluminum plateof 10 nm. The center line average surface roughness Ra of the aluminumplate after the cold rolling was controlled to 0.2 μm by adjusting theroughness of the rolling rolls. Thereafter the plate was subjected totension leveling for the improvement of the flatness thereof.

Then the plate was surface-treated to give a substrate for lithographicprinting plate. First of all, the aluminum plate was degreased bytreating with a 10% aqueous solution of sodium aluminate at 50° C. for30 seconds in order to remove any rolling oil from the surface thereof,neutralized with a 30% sulfuric acid aqueous solution at 50° C. for 30seconds and then subjected to desmutting.

Then the plate or the substrate was subjected to a surface-rougheningtreatment or the so-called surface-graining treatment for improving theadhesion between the substrate and a light-sensitive layer and forimparting water retention characteristics to non-image areas. An aqueoussolution containing 1% nitric acid and 0.5% aluminum nitrate wasmaintained at 45° C., aluminum webs were electrolytically grained byapplying an electric current at a current density of 20 A/dm² using anindirect power supply cells so as to ensure the quantity of electricityat the anode side of 240 coulomb/dm² using an alternating waved currenthaving a duty ratio of 1:1, while passing the webs through the aqueoussolution. Thereafter, the web was etched by immersing in a 10% sodiumaluminate aqueous solution at 50° C. for 30 seconds, neutralized with a30% sulfuric acid aqueous solution at 50° C. for 30 seconds and thendesmutted.

Moreover, the web was anodized to form an anodized film on the substratefor the improvement of the wear resistance, resistance to chemicals andwater retention characteristics. More specifically, the aluminum web wascontinuously passed through a 20% sulfuric acid aqueous solution as anelectrolyte and electrolyzed by applying an electric current at a DCcurrent density of 20 A/dm² using an indirect power supply cells to thusform an anodized film thereon in an amount of 2.5 g/m².

Then the following undercoating liquid 5 was applied onto this aluminumsubstrate with a wire bar such that the coated amount of the dry solidcontent was equal to 5 mg/m² and then dried in a hot air dryer at 90° C.for 30 seconds.

(Undercoating Liquid 5) 2-Aminoethyl-phosphonic acid 0.1 gPhenyl-phosphonic acid 0.1 g Methanol  75 g Water  25 g

Then the following light-sensitive liquid 6 (a coating liquid forforming a light-sensitive layer) was applied to the foregoingundercoating layer-carrying substrate with a wire bar and then dried ina hot air dryer at 115° C. for 45 seconds to give a negativepresensitized plate for forming lithographic printing plates. Thecondition of the coated surface of the presensitized plate was excellentin the uniformity and the coated amount of the light-sensitive liquidwas 1.3 g/m² (Example 24).

(Composition of Light-Sensitive Liquid 6) Component Amt. (g) Light-HeatConversion Agent (Cyanine dye TN-1 having 0.10 the following Structure)Thermally radical-generating agent (sulfonium salt 0.30 compound TN-2having the following structure) Addition-polymerizable unsaturatedcompound 1.00 (dipentaerythritol hexaacrylate) Alkali-soluble binderpolymer (a copolymer of allyl 1.2 methacrylate and methacrylic acid,having a copolymerization molar ratio of 83:17 and a weight averagemolecular weight of 125,000) Coloring agent (Naphthalene-sulfonic acidsalt of Victoria 0.04 Pure Blue) Fluorine atom-containing polymer (P-20)0.005 Methyl ethyl ketone 10.0 Water 8.0

The resulting negative presensitized plate for lithographic printingplate was exposed to light to form 50% half tone dot images usingTrendsetter 3244VF available from Creo Company and equipped with awater-cooled 40W infrared semiconductor laser under the followingconditions: an output of 9W; a rotational frequency of the outer drum of210 rpm, a reverse side energy of 100 mJ/cm²; and a resolution of 2400dpi.

Then the imagewise exposed plate was developed using an automaticdeveloping machine STABRON 900N (available from Fuji Photo Film Co.,Ltd.). The developer and replenisher used were those having thefollowing compositions, respectively, the temperature of the developingbath was set at 30° C., and the finisher used was FN-6 (available fromFuji Photo Film Co., Ltd.) diluted with water (1:1, pH=10.8). As aresult, there were obtained uniform and excellent half tone dot images.The resulting lithographic printing plate was fitted to a printing pressHEIDEL SOR-M (available from Heidelberg Company) to carry out printingoperations. Thus, printed matters of not less than 110,000 wereobtained. Moreover, the light-sensitive liquid used in this example hada low foaming ability, the time required for suppressing foams was foundto be not more than 5 minutes and the surface condition of thelight-sensitive layer was also found to be excellent (pinholedensity=5/m²) (Example 24).

Separately, 1 m² of the presensitized plate for lithographic printingplates was entirely exposed to light, treated with 100 ml of thedeveloper and the developer after the treatment was inspected for thegeneration of any sludge. As a result, it was confirmed that sludge wasnot generated at all and that the presensitized plate was excellent inthe solubility in the developer.

A presensitized plate for preparing lithographic printing plates wasprepared by repeating the same procedures used in Example 24 except thatthe fluorine atom-containing polymer was omitted from the foregoinglight-sensitive liquid. As a result, it was found that thelight-sensitive layer thus obtained was insufficient in the uniformity.Moreover, the presensitized plate was subjected to the samelight-exposing and developing treatments used in Example 24 and it wasthus confirmed that defects were formed on the portions carrying halftone dot images (Comparative Example 15).

The same procedures used in Example 24 were repeated except that R-1 wassubstituted for the fluorine atom-containing polymer used in theforegoing light-sensitive liquid to form a presensitized plate forpreparing a lithographic printing plate. The resulting light-sensitiveliquid had a high foaming ability, the time required for suppressingfoams was found to be not less than 30 minutes and the light-sensitiveliquid was quite insufficient in the production properties. Theresulting light-sensitive layer was found to be insufficient in theuniformity. Moreover, the presensitized plate was subjected to the samelight-exposing and developing treatments used in Example 24 and it wasthus confirmed that defects were formed on the portions carrying halftone dot images (Comparative Example 16).

Separately, 1 m² of the presensitized plate for preparing a lithographicprinting plate was entirely exposed to light, treated with 100 ml of thedeveloper and the developer after the treatment was inspected for thegeneration of any sludge. As a result, it was confirmed that sludge wasclearly generated and that the presensitized plate was inferior in thesolubility and dispersibility in the developer.

It will be clear from the results obtained in Example 24 and ComparativeExample 15 and 16 that the use of the fluorine atom-containing polymeraccording to the present invention would permit the formation of alight-sensitive layer having uniform surface condition, the preparationof a thermally negative lithographic printing plate whose image areasare improved in the resistance to developer and that the light-sensitivelayer is excellent in the solubility and dispersibility in the developerand is thus never accompanied by the generation of any sludge.

As has been described above in detail, the present invention permits theformation of a light-sensitive layer having uniform surface conditionwithout causing abnormality in the surface quality due to the foamingphenomenon observed during the production and also permits theproduction of a positive light-sensitive resin composition havingexcellent solubility and dispersibility in a developer.

Moreover, it has been found that the use of the specific fluorineatom-containing polymer according to the present invention would permitthe improvement of the resulting presensitized plate for preparing alithographic printing plate not only in the foregoing surface qualityand solubility in the developer, but also in the gradation for thenegative type one and permit the improvement of the presensitized platein the sensitivity to laser beams and resistance to fogging caused dueto scattering and reflected light rays, in case of, in particular, alaser light-sensitive photopolymerizable printing plate and thus permitthe preparation of a lithographic printing plate having high printingdurability.

Moreover, it has also been found that the use of the foregoing polymerwould permit the preparation of a heat-sensitive presensitized plate forpreparing a lithographic printing plate improved not only in theforegoing surface quality and solubility in the developer, but also inthe discrimination and the strength of images and therefore, permit thepreparation of a printing plate, which never causes any missing ofimages on the portions touched with the bare hands and which is improvedin the stability or resistance to any external defect.

What is claimed is:
 1. A presensitized plate for preparing alithographic printing plate, which comprises a substrate providedthereon with a light-sensitive layer containing a fluoro-aliphaticgroup-containing copolymer prepared by copolymerizing at least thefollowing monomers (A) and (B): (A) an addition polymerizable monomerhaving, on a side chain, a fluoro-aliphatic group in which hydrogenatoms are replaced with fluorine atoms; and (B) a (meth)acrylate havingan ester chain represented by the following general formula (I) or (II):CH₂═C(R¹)—CO—O—R²—O—(CO—R³—O)_(n)—R⁴  (I)CH₂═C(R¹)—CO—(O—R³—CO)_(n)—O—R⁴  (II) (In the formulas, R¹ represents —Hor —CH₃; R² and R³ each independently represents an alkylene grouphaving 1 to 12 carbon atoms; R⁴ represents a hydrogen atom or asubstituted or unsubstituted alkyl group having 1 to 12 carbon atoms,cycloalkyl group, aryl group, aralkyl group or heterocyclic groupwherein the substituent on the group of R⁴ is selected from the groupconsisting of alkyl or alkoxy group having 1 to 6 carbon atoms and n isa number ranging from 1 to 50).
 2. The presensitized plate for preparinga lithographic printing plate of claim 1, wherein (A) the additionpolymerizable monomer is a vinyl monomer carrying a radicalpolymerizable unsaturated group having, on a side chain, afluoro-aliphatic group in which hydrogen atoms are replaced withfluorine atoms.
 3. The presensitized plate for preparing a lithographicprinting plate of claim 2, wherein the vinyl monomer is an acrylate ormethacrylate compound represented by the general formula:Rf—R′—OOC—C(R″)═CH₂ (wherein R′ represents a single bond, an alkylenegroup, a sulfonamide-alkylene group or a carbonamide-alkylene group; R″represents a hydrogen or halogen atom or a methyl group; and Rfrepresents a perfluoro-aliphatic group).
 4. The presensitized plate forpreparing a lithographic printing plate of claim 1, wherein R² and R³each independently represents an alkylene group having 2 to 6 carbonatoms, and R⁴ represents a hydrogen atom or a substituted orunsubstituted alkyl group having 1 to 6 carbon atoms.
 5. Thepresensitized plate for preparing a lithographic printing plate of claim3, wherein R² and R³ each independently represents an alkylene grouphaving 2 to 6 carbon atoms, and R⁴ represents a hydrogen atom or asubstituted or unsubstituted alkyl group having 1 to 6 carbon atoms. 6.The presensitized plate for preparing a lithographic printing plate ofclaim 1, wherein the amount of the fluoro-aliphatic group-containingmonomer (A) is in the range of 5 to 90% by weight on the basis of thetotal weight of the monomers constituting the fluorine atom-containingpolymer and the weight average molecular weight of the fluorineatom-containing polymer ranges from 3,000 to 200,000.
 7. Thepresensitized plate for preparing a lithographic printing plate of claim1, wherein the amount of the fluorine atom-containing polymer rangesfrom 0.005 to 8% by weight on the basis of the amount of thelight-sensitive resin composition for forming the light-sensitive layer.8. The presensitized plate for preparing a lithographic printing plateof claim 1, wherein an additional monomer copolymerizable with themonomers (A) and (B) is used for the preparation of fluoro-aliphaticgroup-containing copolymer, which the additional monomer is selectedfrom the group consisting of acrylic acid, methacrylic acid, acrylicacid esters, methacrylic acid esters, acrylamides, methacrylamides,allyl compounds, vinyl ethers and vinyl esters.
 9. A method forpreparing a lithographic printing plate, which comprises imagewiseexposing the presensitized plate of claim 1 to light and then developingthe exposed plate with a developer.
 10. The method of claim 9, whereinthe developer comprises (a) at least one saccharide selected fromnon-reducing saccharides and (b) at least one base and having a pH valueranging from 9.0 to 13.5.